QtConcurrent limits resource usage to a global number of simultaneous
threads. That means that if some QtConcurrent based algorithm currently
grabs all threads, any other use of QtConcurrent blocks, which is not
what we want.
Use the new threading methods of C++11 instead, but still use
QFuture(Interface) manually for the progress, result and status
reporting.

Task-number: QTCREATORBUG-14640
Change-Id: I6379d2f2a01b6d200811ef4be0bbfcd4493dd154
Reviewed-by: Orgad Shaneh <orgads@gmail.com>