Better fail clone management

[pmiossec]

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

[KindDragon]

Than you can remove --resumable Clone command line option. User can continue cloning with fetch or branch --init -all

[spraints]

🤘

Could git-tfs write a message that you can cd Project and git tfs fetch --all (or whatever) to finish the clone?

[spraints]

Could git-tfs write a message that you can cd Project and git tfs fetch --all (or whatever) to finish the clone?

... can be something we do in the future.

This is the last thing on the "must have" list for v0.20 (#559). Is it still good to merge? If it is, @pmiossec feel free to hit the Merge button, and I can cut a release this week.

[pmiossec]

@spraints I have displayed the message :) Some refactoring, correction and improvements was needed. Not we could merge...