* AUTHORS: Update from GPLv2 to GPLv3.
* Makefile.am: Likewise.
* NEWS: Likewise.
* README: Likewise.
* README-hacking: Likewise.
* bootstrap: Likewise.
* bootstrap.conf: Likewise.
* configure.ac: Likewise.
* exgettext: Likewise.
* doc/Makefile.am: Likewise.
* lib/Makefile.am: Likewise.
* lib/cmpbuf.c: Likewise.
* lib/cmpbuf.h: Likewise.
* lib/prepargs.c: Likewise.
* m4/vararrays.m4: Likewise.
* man/Makefile.am: Likewise.
* ms/Makefile.am: Likewise.
* ms/README: Likewise.
* ms/config.bat: Likewise.
* ms/config.sed: Likewise.
* ms/config.site: Likewise.
* po/POTFILES.in: Likewise.
* src/Makefile.am: Likewise.
* src/analyze.c: Likewise.
* src/cmp.c: Likewise.
* src/context.c: Likewise.
* src/diff.c: Likewise.
* src/diff.h: Likewise.
* src/diff3.c: Likewise.
* src/dir.c: Likewise.
* src/ed.c: Likewise.
* src/io.c: Likewise.
* src/normal.c: Likewise.
* src/sdiff.c: Likewise.
* src/system.h: Likewise.
* src/util.c: Likewise.