libgit2 version 0.10.0, "very disco"

A version *so* awesome that needs 2 version bumps AND a codename.

Major features:

	- New internal garbage collection (harder)
	- Pack backend rewritten from scratch (better)
	- Revision walker rewritten from scratch (faster)
	- New object interdependency system (stronger)
	- Unique OID shortener
	- Reference listing

In honor of one heck of a music album, released ten years ago,
yesterday.

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>

Add proper version management

We now have proper sonames in Mac OS X and Linux, proper versioning on
the pkg-config file and proper DLL naming in Windows.

The version of the library is defined exclusively in 'src/git2.h'; the build scripts
read it from there automatically.

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

Set short message when changing a commit's message

Yes, finally.

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

tagging initial release of libgit2