qdoc now searches for .qdoc files in the directories
listed in the exampledirs variable. These files are
added to the list of sources to be parsed.

Task nr: QTBUG-26708

Change-Id: I6dfd7cd7b41e0bdf847f88b6d61ac0272902d4e1
Reviewed-by: Casper van Donderen <casper.vandonderen@nokia.com>