Qbs: Move setting up the build directory out of createBuildInfo

Change-Id: Ief088f880c866e8293c191194da05185f5df937a
Reviewed-by: Tobias Hunger <tobias.hunger@digia.com>
Qbs: Remove unused method

Change-Id: Ib25b5155ac267cee7146bca22ac599ad96e4580b
Reviewed-by: Tobias Hunger <tobias.hunger@digia.com>
Qbs: Handle empty builddirectories in our buildconfigurationfactory

Change-Id: Id92b7345391937f27663810ad03018b1e263fb22
Reviewed-by: Tobias Hunger <tobias.hunger@digia.com>
Qbs: Honor default build directory set up in Build & Run->General

Change-Id: I1e7d6cc97f2e8adb5956866205493d28d79887cb
Reviewed-by: Tobias Hunger <tobias.hunger@digia.com>
Doc: support for Mac OS X 10.6 was dropped

Change-Id: Ic9f13c5303f6caa14ca5b3279a7f7509b9e12b73
Reviewed-by: Eike Ziller <eike.ziller@digia.com>