clients: add ime-keyboard(input_method), text-entry(text_input)

clients: add ime-keyboard(input_method), text-entry(text_input)

ime-keyboard
 - deals with input_method
 - input key event
   usage) key [keys index] [down=1/up=0] ( keys = [q,w,e,r,t,,,,] )
      ex) key 1 1 (input 'w' key)
          key 1 0
          key 2 1 (input 'e' key)
          key 2 0

text-entry
 - deals with text_input
 - when mouse enters into the surface and mouse is pressed,
   text_input is activated.
   when mouse is released, text_input is deactivated.
 - usage) when text_input is activated, this gets key event from
   input_method.

Change-Id: Idbea6f4d5756cfcb65f2810f4a3967669ff04045