The -Qualifier code for Split-Path made some incorrect assumptions:
* That a path only referred to the file system
* That drives cannot be used on Unix systems
These assumptions were both wrong, so I've reverted the change so we
do not have any Unix specific code in Split-Path now.
Fixes#1176
This restructuring moves tests to a directory name which matches the module
in which the cmdlet resides which should improve the discoverability of a
specific test.
For tests which are not about cmdlets in a module, new directories have been
created to make those tests easier to find as well
Sergei Vorobev