status data types
add ByIndex, reorder to match other files
add StatusList.EntryCount()
add StatusList() to Repository
start on status tests; fix bug in Repository.StatusList()
add status option support
add StatusFile function
comment out issue with entry count
add git_status_foreach binding
don't return anything from StatusList.Free
remove status_foreach binding
add thread locking to status api
fix status list to handle null head_to_index in entries
Repository.CreateCommit: Allow empty refname for non-update commit
Update clone options to be in sync with libgit2 master.

Remove missing constants.
Repository.CreateCommit: Only allocate CStr on non-empty refname
Merge pull request #115 from surma-dump/feature/empty_refname

Repository.CreateCommit: Allow empty refname for non-update commit
Merge pull request #113 from CMGS/master

enhance checkout, add CheckoutTree method
give status option flags their own type
remove unused status version field