Made QQuickTextInput follow input direction changes

Cursor of empty field should align based on input method
direction. Now input method allowed to change direction
on run time.

Also earlier cursor wasn't properly drawn on correct alignment
at all.

Change-Id: I4601f10e6b5dde09591bd484b05f001add6c1573
Reviewed-by: Andrew den Exter <andrew.den-exter@nokia.com>
Reviewed-by: Joona Petrell <joona.t.petrell@nokia.com>