Some fixes to PowerLine prompt + New command

Start-GitHubDirDownload - Download a specific directory using
github's SVN support. Requires subversion package be installed.

base/Start-GitHubDirDownload.ps1

@@ -0,0 +1,61 @@
+[CmdletBinding()]param(
+    [Parameter(Mandatory)]
+    [string]$GitHubProject,
+    [string]$Directory,
+    [string]$Destination='.',
+    [switch]$Update,
+    [string]$BackupRelativePath="<auto>"
+)
+
+$local:testReq = $(try {
+    Invoke-WebRequest "https://github.com/$GitHubProject/tree/HEAD/$Directory" -UseBasicParsing -ErrorAction Stop
+    } catch {})
+if( 200 -ne $testReq.StatusCode ) {
+    Write-Verbose $($testReq|Format-List|Out-String)
+    Write-Error "Request failed for $GitHubProject : $Directory"
+    return
+}
+
+$DestFull = Get-Item $(Join-Path $Destination '.')
+Write-Verbose "DestFull: $($DestFull | Format-List | Out-String)"
+
+$local:tmpFile = ""
+New-TemporaryFile | Select-Object -ExpandProperty FullName -OutVariable tmpFile | Remove-Item -Force
+$tmpPath = New-Item -ItemType Directory $tmpFile
+Remove-Variable tmpFile
+Push-Location $tmpPath
+Write-Verbose "tmp $($tmpPath.FullName) created"
+
+if( $BackupRelativePath -eq "<auto>" ) {
+    $BackupRelativePath = ".overitten.on.#Timestamp#"
+}
+$BackupRelativePath = $BackupRelativePath -replace "#Timestamp#",$(Get-Date -Format "yyyyMMdd-HHmmss")
+
+Write-Verbose "Fetching $Directory..."
+$null = & svn checkout "https://github.com/$GitHubProject/trunk/$Directory"
+$local:dirName = Split-Path -Leaf $Directory
+
+Remove-Item -Recurse (Join-Path $dirName '.svn') -Force 
+
+Get-ChildItem -File -Force $dirName -Recurse | ForEach-Object {
+    $local:item = $_.FullName.Replace($tmpPath.FullName,'') -replace '^/',''
+    $local:dst = Join-Path $DestFull.FullName $item
+    if( Test-Path $dst ) {
+        if( -not $Update ) {
+            Write-Verbose "$dst already exists, skipping..."
+            return
+        }
+        if( -not (Compare-Object (Get-Content $item) (Get-Content $dst) -CaseSensitive) ) {
+            Write-Verbose "$dst already updated, skipping..."
+            return
+        }
+        $local:bkPath = Join-Path $DestFull.FullName (Split-Path -Parent $item) $BackupRelativePath (Split-Path -leaf $item)
+        $null = New-Item -ItemType Directory -Force (Split-Path -Parent $bkPath) -ErrorAction Stop
+        Move-Item -Force $dst $bkPath
+    }
+    Write-Verbose "Copy-Item -Force $_ $dst -PassThru"
+    Copy-Item -Force $_ $dst -PassThru
+}
+
+Pop-Location
+Remove-Item -Recurse $tmpPath -Force