Mobile apps should use a prompt dialog instead of the inline text entry field.  Should fix the issue of focus weirdness and non-appearing virtual keyboard.
Review URL: https://codereview.appspot.com/9124046

git-svn-id: http://blockly.googlecode.com/svn/trunk@874 c400ca83-b69d-9dd7-9705-49c6b8615e23