Add lipi-toolkit implementation of handwriting input method

This change adds a reference implementation of the handwriting
input method.

The handwriting support is enabled by adding CONFIG+=lipi-toolkit
to the qmake command line.

The current implementation uses alphanumeric model for handwriting
recognition, which come bundled in the lipi toolkit.

Change-Id: I1fcc0a0c0620dd7f9503a2a584cea0003e8a032e
Reviewed-by: Gatis Paeglis <gatis.paeglis@theqtcompany.com>