Summary of changes

• Fix bug in Repository.prototype.refreshReferences where new remote references from a new remote added/fetched on a separte repo instance do not show up in the result.
• Fixed a prototype problem with cherrypick, merge, and other collections that have a function at their root. call, apply, and bind should now be on NodeGit.Cherrypick.
• Bumped libssh2 to resolve security notice.

Merged PRs into NodeGit

• Bump libssh2 to 1.8.2 and fix some npm audit warnings #1678
• Root functions should keep their function prototypes correctly #1681
• refresh_references.cc: bust LibGit2 remote list cache by reading config #1685