Escape colon in synced folder id

This is a actual for Windows guests, where colon is the part of any absolute path.
Parallels Desktop replaces colons (:) by asterisks (*) on the guest side,
so, it breaks the synced folder mapping for Vagrant.

lib/vagrant-parallels/synced_folder.rb

@@ -105,7 +105,7 @@ def driver(machine)
       end
 
       def os_friendly_id(id)
-        id.gsub(/[\/]/,'_').sub(/^_/, '')
+        id.gsub(/[\/:]/,'_').sub(/^_/, '')
       end
     end
   end