Add pycosat.
fix perl build failures

(cherry picked from commit 94c1406951edb37670740f3218a6e064be768555)
Signed-off-by: Domen Kožar <domen@dev.si>
ghc-head: upgrade to 2014-12-10
mkvtoolnix: fix to find boost lib
dvdauthor: fix building against glibc 2.20

and 2 other patches from redhat
Merge pull request #5321 from teh/master

Add pycosat.
added tmsu, a tool for tagging your files
Add nix-serve
nix: Update to 1.8
nix-repl: Update