Add a dereference method to Rugged::Reference to dereference refs to tags
Use rugged_str_new2 rather than rb_str_new2
Free the git object and better length handling
Rename Rugged::Reference#dereference to Rugged::Reference#peel
Merge remote-tracking branch 'origin/development' into ref-dereference
Merge pull request #208 from adelcambre/ref-dereference

Add a #peel method to reference objects