Bump the version number to 0.8.0

Yes, these are some seriously massive changes to the external API. We
are breaking stuff.

Signed-off-by: Vicent Marti <tanoku@gmail.com>

include/git2.h

@@ -26,9 +26,9 @@
 #ifndef INCLUDE_git_git_h__
 #define INCLUDE_git_git_h__
 
-#define LIBGIT2_VERSION "0.4.0"
+#define LIBGIT2_VERSION "0.8.0"
 #define LIBGIT2_VER_MAJOR 0
-#define LIBGIT2_VER_MINOR 4
+#define LIBGIT2_VER_MINOR 8
 #define LIBGIT2_VER_REVISION 0
 
 #include "git2/common.h"