Use accounts.getCurrentAccount instead of users.get_current_user
This way accounts are normalized, which is usefull now that debug
mode is also available even if deployed on appspot.com.
Patch by: Sverre Rabbelier
isDebug now also checks melange version
To facilitate this getMelangeVersion was introduced and in order to
not show the 'Flush Cache' button a isLocal method was also added.
Patch by: Sverre Rabbelier