Refacto calls to Garbage Collection
Merge pull request #571 from pmiossec/refacto_garbage_collect

Refacto calls to Garbage Collection
Don't cleanup clone directory when fail fetch during `clone`

It's a shame to end with a clean directory after (perhaps)
hours of fetching history because a problem during a fetch
cleanup workspace directory even when fetch problems
update release note
Merge branch 'better_fail_clone_management' into rename_branch

Conflicts:
	GitTfs/Commands/Clone.cs
	GitTfs/Commands/InitBranch.cs
typo