log in/log out rewrite

Delete network object after logging out. related to #262
Support for multiple log in. related to #263 
Activate the tab if we already have one open and catch tab is closed #328 
Close a tab if user denies access #475 

I'll follow up with cl fixing storage state.
Are you sure we should be using the displayName?  For GTalk, the displayName will be "Google", while the name will be "google".  In the past all code used the lowercase "google" as the network name, and displayName was just added yesterday and is only used in notifications shown to the user.  Seems like the regular name would be safer to use