prepare a fresh  experimental branch

git-svn-id: https://foundry.supelec.fr/svn/luatex/branches/experimental@4691 0b2b3880-5936-4365-a048-eb17d2e5a6bf
a fresh experimental branch

git-svn-id: https://foundry.supelec.fr/svn/luatex/branches/experimental@4692 0b2b3880-5936-4365-a048-eb17d2e5a6bf
Fix for issue 828 and 845

git-svn-id: https://foundry.supelec.fr/svn/luatex/branches/experimental@4693 0b2b3880-5936-4365-a048-eb17d2e5a6bf
Issue 801: adapt liolibext.c to accept largefiles under Windows with mingw

git-svn-id: https://foundry.supelec.fr/svn/luatex/branches/experimental@4694 0b2b3880-5936-4365-a048-eb17d2e5a6bf
fix issue 801 under Windows

git-svn-id: https://foundry.supelec.fr/svn/luatex/branches/experimental@4695 0b2b3880-5936-4365-a048-eb17d2e5a6bf