git related improvements and implementations

+ Get-GitRepo - Clone or update a repo, with tag support
+ Get-GitHubReleaseTag - Grab tag from latest release page
+ Refresh-GitRepo - Stage all possible changes, discarding any
previously stageds changes
= GitHub repo is now git repo - as some code isn't GitHub specific
+ cat Alias for Get-Content
= Get-PossiblArguments improvement
= Invoke-WebDownload fix
= dcedit fixing bad argument processing

base/Aliases/cat.ps1

@@ -0,0 +1 @@
+Get-Content