Add new lgpl rules with libtool exception

Solves aboutcode-org#1912

Signed-off-by: Ayan Sinha Mahapatra <ayansmahapatra@gmail.com>

src/licensedcode/data/rules/lgpl-2.0-plus_with_libtool-exception-2.0_1.RULE

@@ -0,0 +1,20 @@
+GNU Libltdl is free software; you can redistribute it and/or
+modify it under the terms of the GNU Lesser General Public
+License as published by the Free Software Foundation; either
+version 2 of the License, or (at your option) any later version.
+
+As a special exception to the GNU Lesser General Public License,
+if you distribute this file as part of a program or library that
+is built using GNU Libtool, you may include this file under the
+same distribution terms that you use for the rest of that program.
+
+GNU Libltdl is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public
+License along with GNU Libltdl; see the file COPYING.LIB.  If not, a
+copy can be downloaded from  http://www.gnu.org/licenses/lgpl.html,
+or obtained by writing to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.

src/licensedcode/data/rules/lgpl-2.0-plus_with_libtool_exception-2.0_1.yml

@@ -0,0 +1,7 @@
+license_expression: lgpl-2.0-plus WITH libtool-exception-2.0
+is_license_notice: yes
+minimum_coverage: 90
+referenced_filenames:
+    - COPYING.LIB
+ignorable_urls:
+    - http://www.gnu.org/licenses/lgpl.html