user-friendly error messages
Merge pull request #136 from oakkitten/user-friendly-error-messages

user-friendly error messages
forget lines & nicks when closing a buffer if are not getting updates for closed buffers
Merge pull request #143 from oakkitten/only-sync-open

forget lines & nicks when closing a buffer if are not getting updates for closed buffers
Browser.EXTRA_CREATE_NEW_TAB is API level 12

* Instead, don't set Browser.EXTRA_APPLICATION_ID.
Add TCP keepalive

This doesn't include realtime updates to the current connection
when the preferences are changed, although that would be possible.