Add a .gitignore.

.gitignore

+ChangeLog
+Makefile
+Makefile.in
+aclocal.m4
+autom4te.cache/
+config.guess
+config.h
+config.h.in
+config.log
+config.status
+config.sub
+configure
+depcomp
+install-sh
+libtool
+libvdpau-*.tar.bz2
+libvdpau-*.tar.gz
+ltmain.sh
+missing
+.deps
+.libs
+*.lo
+*.la
+*.o
+stamp-h1
+vdpau.pc