Ignore downloaded & built files in contribs

extras/contrib/.gitignore

+bin
+include
+lib
+info
+man
+share

extras/contrib/src/.gitignore

+*.tar.gz
+*.tar.bz2
+*.tgz
+*.zip
+.*
+!.gitignore
+a52dec
+dirac
+faac
+faad2
+ffmpeg
+flac
+freetype2
+fribidi
+gettext
+gnutls
+goom
+lame
+libcaca
+libdc1394
+libdca
+libdvbpsi
+libdvdcss
+libdvdnav
+libebml
+libgcrypt
+libgpg-error
+libiconv
+libid3tag
+libmad
+libmatroska
+libmodplug
+libogg
+libpng
+libraw1394
+libtheora
+libvorbis
+live
+mpcdec
+mpeg2dec
+speex
+twolame
+wxwidgets
+x264
+xml
+zlib