[Qt-creator] Build output parser and recursive make

[Daniel Teske]

> How non-trivial would it be to help it understand Cygwin-style paths?
Pretty easy.

The two parts which are interesting to you are:
*void GnuMakeParser::taskAdded(const Task &task)*
which converts a filename into a absolute path and
*void GnuMakeParser::stdOutput(const QString &line)*
which tracks parses the Entering and Leaving messages.

The code keeps track of multiple directories to correctly support "-j".

I think the code might have been in a different place in 2.0

daniel