+ Windows `net use` frontend written in PowerShell

Features:
+ Ask for location to be mapped
+ Ask for user credentials using $Host.ui.PromptForCredential (better than Get-Credential cmdlet)
+ Complain about empty location, username or password
+ Show `net use` output to user

Notes / TBD
* Can't use PSDrive because it only works in PowerShell context and `net use` works systemwide
* Must add a statusbar on the main form to display the "empty location" message
* Must interpret `net use` errors to the user instead of print the raw response
* Handle the main cancel action to close the program
* Rework main form attributes