Make it easier to select words at the start of a line.

Make it easier to select words at the start of a line.

QTextControl's word selection will only include a word if the cursor
position is past the mid point of the word. This can make it
difficult to select words near the edges of the screen on touch
devices.  For the TextEdit word selection mode select a word ignore
the relative position within a word.

Task-number: QT-5206
Task-number: QTBUG-20719
Change-Id: I77e71e01d8021d66ada785cf894ba876faccefdf
Reviewed-by: Joona Petrell <joona.t.petrell@nokia.com>