Fix GnuTLS to not need this hack anymore.
Merge pull request #1 from Robby-/master+gnutlsfix

Fix GnuTLS to not need this hack anymore.
[ci skip] MySQL
Remove travis specific fixes, too much work
MySQL requires a newer mingw version (with gcc 4.8) while other packages like gnutls require 4.6, so don't build it by default