Propose unified rev-parse API
Implement unified git_revparse
Deprecate git_revparse_single and _rangelike
Add rev-list example to makefiles
Reintroduce git_revparse_single.
Redeploy git_revparse_single.
Change git_revparse to output git_object pointers

This will probably prevent many lookup/free
operations in calling code.
Clean up example code.
Clean up minor details
Merge remote-tracking branch 'ben/unified-revparse' into development
Allow git_remote_ls after disconnecting from the remote

Keep the data around until free, as expected by our own fetch example
Is this crazy?
git_revision -> git_revspec
Update docs
remote: don't try to update FETCH_HEAD if no extra heads exist

Don't try to update anything if there are no heads to update. This
saves us from trying to look into a fetch refspec when there is none.

A better fix for compatibility with git when using remotes without
refspecs is still needed, but this stops us from segfaulting.
Fix examples
Merge pull request #1470 from carlosmn/remote-ls-after-close

Fetch fixes
Merge pull request #1469 from libgit2/vmg/unified-revision

Unified rev-parse, with a revision object