Removed 'select_tab' action. Use touch('...') instead.

This was no working reliably for TabHosts. It was crashing on Jelly Bean+
devices.
Removed 'wait_for_dialog_to_close' action and "I wait for dialog to
close" predefined step.

The action did not work reliably for dialog fragments. Use standard
queries to wait a dialog to close. In the future we wish to provide a
simple, general solution to dialogs.
Added wait_for_activity method.
Removed 'wait_for_screen' action. Use wait_for_activity ruby method instead.