Adding Posh.ExtensionCollection get_All (Fixes #128)

Posh.types.ps1xml

@@ -820,6 +820,44 @@ Get-History -Id $historyIDS
   <Type>
     <Name>Posh.ExtensionCollection</Name>
     <Members>
+      <ScriptProperty>
+        <Name>All</Name>
+        <GetScriptBlock>
+                        &lt;#
+.SYNOPSIS
+    Gets all items in an extension collection.
+.DESCRIPTION
+    Gets all items in a collection of extended commands.
+#&gt;
+if (-not $this.'.Cache') {
+    if (-not $this.'.Module') { return @() }
+
+    $findExtensionArgs  = @($this.'.Module') + @($this.'.Path')
+    $allExtensionsFound = 
+        @(:nextExtension 
+            foreach ($foundExtension in 
+                $posh.Commands.FindExtensions.Invoke($findExtensionArgs)
+            ) 
+            {
+            if ($this.'.CommandType') {
+                foreach ($typename in $this.'.CommandType') {
+                    if ($foundExtension.pstypenames -contains $typename) {
+                        $foundExtension
+                        continue nextExtension
+                    }
+                }
+            } else {
+                $foundExtension
+            }
+            }
+        )
+    $this |
+        Add-Member NoteProperty '.Cache' $allExtensionsFound -Force
+}
+
+return $this.'.Cache'
+                    </GetScriptBlock>
+      </ScriptProperty>
       <ScriptProperty>
         <Name>CommandType</Name>
         <GetScriptBlock>