[Development] Qt 4.x and Qt 5 frameworks should use @rpath (QTBUG-31814)

[Adam Strzelecki]

The changes for qtbase are there:

	https://codereview.qt-project.org/91669
	https://codereview.qt-project.org/91670
	https://codereview.qt-project.org/91671
	https://codereview.qt-project.org/91672
	https://codereview.qt-project.org/91673
	https://codereview.qt-project.org/91674
	https://codereview.qt-project.org/91675
	https://codereview.qt-project.org/91676

This makes Qt SDK build:
(1) completely relocatable once installed
(2) all tools and examples refer frameworks relatively
(3) there is no hardcoded SDK in any framework or tool (except qmake which keep SDK prefix)

Next steps:
(1) changes to macdeployqt (removing absolute rpath & rewrite)
(2) remove rewriting in installer-framework

FYI since installer rewrites absolute paths in frameworks, and there a none now this shouldn't have impact on Mac SDK installer itself.

Waiting for feedback.

Regards,
-- 
Adam