Let unshelve continue after errors.
Refactor.
Update docs.
Update libgit2sharp to v0.18.1
Use the good Signature
Change call to CreateCommit() because used api is obsolete
Update libgit2sharp to v0.19
Update rcheckin.md
Merge pull request #638 from pmiossec/update_libgit2sharp

Update libgit2sharp to v0.19
unshelve --force ignores errors while `Get`ing files.
Make the unshelve --force warnings shorter.
Merge pull request #636 from spraints/ignore-unshelve-errors

Add the option to ignore unshelve errors
Method GetChangesets() only for tfs2008 to avoid bad changesets returned when getting by lots

Expected fix #642
Try without the Retry.Do()
Correct the double fetch of changesets
Directly as if "Is2008OrOlder"