GPL-2.0: More alt/optional entries to match FSF's canonical text/plain

These changes address the additional differences between the FSF's
text/plain version [1] (unchanged since 2007-07-16 according to the
Internet Archive [2]) and the FSF's HTML version [3].  There has been
previous work in this direction in e9eb557 (Merge pull request spdx#496
from mlinksva/patch-9, 2017-12-15) and f2b71bd (GPL-2.0: Mark
postal-code commas as optional, 2017-12-14, spdx#514).

The final paragraph ("This General Public License does not permit...")
is in both the text/plain and HTML FSF versions.  I'm not clear on why
it wasn't included in our template (our GPL-3.0 template does include
a similar paragraph).  I've put it in a new <optional> block to cover
folks who were using the text we previously recommended (which lacked
the paragraph).

[1]: https://www.gnu.org/licenses/old-licenses/gpl-2.0.txt
[2]: https://web.archive.org/web/20070716031727/https://www.gnu.org/licenses/old-licenses/gpl-2.0.txt
[3]: https://www.gnu.org/licenses/old-licenses/gpl-2.0.en.html

src/GPL-2.0-only.xml

@@ -38,7 +38,7 @@
       </p>
     </titleText>
     <p>
-      Copyright (C) 1989, 1991 Free Software Foundation, Inc.<br></br>
+      Copyright (C) 1989, 1991 Free Software Foundation, Inc.<alt name="incComma" match="|,"/><br/>
       51 Franklin Street, Fifth Floor, Boston, MA 02110-1301<optional>,</optional>
       USA
     </p>
@@ -104,6 +104,7 @@
       distribution and modification follow.
     </p>
     <p>
+      <alt name="termsTitle" match="|GNU GENERAL PUBLIC LICENSE"/>
       TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
     </p>
     <list>
@@ -400,10 +401,10 @@
         the "copyright" line and a pointer to where the full notice is found.
       </p>
       <p>
-        <optional>&lt;</optional>one line to give the program's name and an idea of what it does.<optional>&gt;</optional>
+        <optional>&lt;</optional>one line to give the program's name and <alt name="ideaArticle" match="an|a brief">an</alt> idea of what it does.<optional>&gt;</optional>
         <br></br>
         Copyright (C)
-        <optional>&lt;</optional>yyyy<optional>&gt;</optional>
+        <optional>&lt;</optional><alt name="templateYear" match="yyyy|year">yyyy</alt><optional>&gt;</optional>
         <optional>&lt;</optional>name of author<optional>&gt;</optional>
       </p>
       <p>
@@ -455,6 +456,15 @@
 	1 April 1989 Ty Coon, President of Vice
       </p>
     </optional>
+    <optional>
+      <p>
+        This General Public License does not permit incorporating your program into
+        proprietary programs.  If your program is a subroutine library, you may
+        consider it more useful to permit linking proprietary applications with the
+        library.  If this is what you want to do, use the GNU Lesser General
+        Public License instead of this License.
+      </p>
+    </optional>
     </text>
   </license>
 </SPDXLicenseCollection>

src/GPL-2.0-or-later.xml

@@ -17,7 +17,7 @@
       </p>
     </titleText>
     <p>
-      Copyright (C) 1989, 1991 Free Software Foundation, Inc.<br></br>
+      Copyright (C) 1989, 1991 Free Software Foundation, Inc.<alt name="incComma" match="|,"/><br/>
       51 Franklin Street, Fifth Floor, Boston, MA 02110-1301<optional>,</optional>
       USA
     </p>
@@ -83,6 +83,7 @@
       distribution and modification follow.
     </p>
     <p>
+      <alt name="termsTitle" match="|GNU GENERAL PUBLIC LICENSE"/>
       TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
     </p>
     <list>
@@ -436,6 +437,15 @@
 	1 April 1989 Ty Coon, President of Vice
       </p>
     </optional>
+    <optional>
+      <p>
+        This General Public License does not permit incorporating your program into
+        proprietary programs.  If your program is a subroutine library, you may
+        consider it more useful to permit linking proprietary applications with the
+        library.  If this is what you want to do, use the GNU Lesser General
+        Public License instead of this License.
+      </p>
+    </optional>
     </text>
   </license>
 </SPDXLicenseCollection>

src/GPL-2.0.xml

@@ -39,7 +39,7 @@
       </p>
     </titleText>
     <p>
-      Copyright (C) 1989, 1991 Free Software Foundation, Inc.<br></br>
+      Copyright (C) 1989, 1991 Free Software Foundation, Inc.<alt name="incComma" match="|,"/><br/>
       51 Franklin Street, Fifth Floor, Boston, MA 02110-1301<optional>,</optional>
       USA
     </p>
@@ -105,6 +105,7 @@
       distribution and modification follow.
     </p>
     <p>
+      <alt name="termsTitle" match="|GNU GENERAL PUBLIC LICENSE"/>
       TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
     </p>
     <list>
@@ -401,10 +402,10 @@
         the "copyright" line and a pointer to where the full notice is found.
       </p>
       <p>
-        <optional>&lt;</optional>one line to give the program's name and an idea of what it does.<optional>&gt;</optional>
+        <optional>&lt;</optional>one line to give the program's name and <alt name="ideaArticle" match="an|a brief">an</alt> idea of what it does.<optional>&gt;</optional>
         <br></br>
         Copyright (C)
-        <optional>&lt;</optional>yyyy<optional>&gt;</optional>
+        <optional>&lt;</optional><alt name="templateYear" match="yyyy|year">yyyy</alt><optional>&gt;</optional>
         <optional>&lt;</optional>name of author<optional>&gt;</optional>
       </p>
       <p>
@@ -456,6 +457,15 @@
 	1 April 1989 Ty Coon, President of Vice
       </p>
     </optional>
+    <optional>
+      <p>
+        This General Public License does not permit incorporating your program into
+        proprietary programs.  If your program is a subroutine library, you may
+        consider it more useful to permit linking proprietary applications with the
+        library.  If this is what you want to do, use the GNU Lesser General
+        Public License instead of this License.
+      </p>
+    </optional>
     </text>
   </license>
 </SPDXLicenseCollection>