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.
I believe right now extractCode will be called any time any tab changes, including tabs that we don't create using chrome.tabs.create.  If thats the case, it seems safer to ensure that we don't close or read any access code from tabs we didn't create