Trim whitespaces from path names.

Task-number: QTIFW-276

At least on windows CreateDirectory will trim them anyway, so
the shortcut operation will fail as the created directory does
not match the arguments passed.

Change-Id: I76466ef1d83461559c51021ad2bedaf36a145f51
Reviewed-by: Tim Jenssen <tim.jenssen@digia.com>