Improve default randomness of thin directory

This will reduce the usage of ``--rand-thin-dir` since the FQDN of the
machine is also included in the remote temporary directory name.
Add last `EOF` to shim deployment code
Add further clarification that gitfs auth is pygit2-only
Merge pull request #16749 from terminalmage/gitfs-docs

Add further clarification that gitfs auth is pygit2-only
Merge pull request #16747 from s0undt3ch/hotfix/add-last-EOF-to-shim

Add last `EOF` to shim deployment code
Merge pull request #16743 from s0undt3ch/hotfix/repetitive-random-ssh-remote-dir

Improve default randomness of thin directory
Merge branch '2014.7' into develop