Merging ActionBar menu with options menu.

Options menu items may now specify if they would like to appear in the
action bar. Menu items defined in xml may set the showAsAction
attribute to one of "never"(default), "ifRoom", or "always". Action
buttons are populated as follows:

* All showAsAction="always" items become action buttons, even if it
  would crowd the navigation area of the action bar.

* If there is space remaining, showAsAction="ifRoom" items are added
  until no more will fit comfortably.

Action button click events are now handled by the
onOptionsItemSelected method used by the standard options menu.

The construction of options menus now happens earlier in order to
provide data to the action bar. Activities with an action bar can now
expect to have onCreateOptionsMenu called when activity start-up is
complete.

Activity#invalidateOptionsMenu can be used to force a refresh of menu
items where the previous API would use ActionBar#updateActionMenu.

Change-Id: If52ddf1cf9f6926206bcdeadf42072ea2c24fab9
18 files changed