Qt Formatter: Be less picky about file urls

Accept colon, space or tab after the location (url:line and optional :column).

Apparently in QML each and every error message is built up as the responsible
developer thinks it makes the most sense and no two seem to agree on a common
format.

Task-number: QTCREATORBUG-10692
Change-Id: I103ae6eeb12b427cce2069db7da5d98a0737bda6
Reviewed-by: Christian Stenger <christian.stenger@digia.com>