[license] Clarify and fix a few typos.

We clarify and fix some problems identified in #266, tho these are
minor (other than bad writing) as LGPL-2.1+ as used by Coq already
allows to consider code to be GPL-3+ if desired.

Fixes #266

LICENSE

@@ -2,26 +2,22 @@ Format: http://www.debian.org/doc/packaging-manuals/copyright-format/1.0/
 Upstream-Name: coq-serapi
 Upstream-Contact: Emilio J. Gallego Arias <e@x80.org>
 Source: https://github.com/ejgallego/coq-serapi
-License: LGPL-2.1+ / GPL-3+
-Copyright: 2016, MINES ParisTech
+License: LGPL-2.1+
+Copyright: 2016-2022, MINES ParisTech / Inria
 
 Authors: Emilio J. Gallego Arias
 
-Files: doc/*
-License: GPL-3+ / CC-BY-SA 3.0 / LGPL-2.1+
+Files: notes/*
+License: LGPL-2.1+ / CC-BY-SA 3.0
 
-Files: sertop/*
-License: GPL-3+ / AGPL-3+
+Files: jscoq/*
+License: GPL-3+
 
 Files: tests/genarg/*
 Authors: Karl Palmskog
 Licence: Derived from many projects as test cases, likely fall into fair-use
 
-Comment: the intent is to be compatible with Coq, however we favor
-GPL-3.
-
-We currently have very little direct derivative from Coq, however
-using LGPL 2.1 seems the safest for now, but we may move to GPL-3 at
-some point, and definitively we double license everything under the
-GPL3 or at your option, any later version.
+Comment: the intent is to be compatible with Coq's license. Note that
+the LGPL-2.1+ allows to treat the code as GPL-3+ , and we favor that. In some,
+like when linking with jsCoq's code, the resulting .js file will be GPL-3+.