In an effort to speed up the prompt we will only call write-vcsstatus if
there is a .git folder in the current or any parent path recursively.
As this function is called every new prompt line it needs to be as fast as
possible.
Explicitly call `import posh-git` because it doesn't have a module
manifest thus powershell can't autoload it when using a cmdlet.
At present the cmder repo doesn't try to download posh-git so it might be
missing from the users session.
This matches how cmd looks in conemu for cmder and PS seems to add some
padding around command output so I really don't see what the extra new
line is doing.
Saving dat precious vertical space.
This should be faster too as we won't automatically import all functions
to the session. Powershell now knows where to look before declaring they
don't exist.
