Tp.PracticePage: removed unneeded properties (has_preedit, preedit, input, attr_input, attr_present)
		 and also moved finger tracking functionality to Tp.FingerPracticePage
Tp.FingerPracticePage: removed redundant code, register signal by ui file.
Tp.FingerStick: give the finger drawing area a required height, so that a small finger also can be displayed well.
Tp.HandWidget: Show all finger sticks.