maint: don’t get fdl.texi from Gnulib

This reverses the 2012-01-13T09:39:45Tmeyering@redhat.com patch,
as Gnulib’s fdl.texi module now says “Don't use this module!”
* bootstrap.conf (gnulib_modules): Remove fdl.
* doc/.gitignore: Don’t ignore fdl.texi.
* doc/fdl.texi: New file, copied from Gnulib.
3 files changed