Add insert, add a contact, and edit name to group activity

* Remove fragment pager and move metadata loading
  back to the group members fragment since we're not
  going to use the old edit fragment any more.
* Bind the autocomplete adapter in the main group
  activity and add an add icon to the options menu
  to search for new contacts.
* Add account selection to the main group activity
  to supports inserts.
* Change the group name dialog added in ag/1040856
  since it supports both adding and updating group
  names now.
* Extract Member inner class from the edit fragment
  since it is needed for the autocomplete view
  and the edit fragment is going away.

Bug 28707265
Bug 18641067

Change-Id: I6b1326ee93dcb75198166e42272c44c983340e27