CMake: Remove copy-pasto for the IMPORTED_LOCATION

Task-number: QTBUG-32579

Change-Id: Ibe9dd92824091989168fca842a59b556937b1f08
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@digia.com>
Reviewed-by: Stephen Kelly <stephen.kelly@kdab.com>
CMake: Add a clean_path before returning a path.

The $$path may already be absolute, so prepending a slash may
result in //usr/lib, for example.

Task-number: QTBUG-32570

Change-Id: If7a4f6fbec0216404cfe48c1da62d21d75b3e272
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@digia.com>
Reviewed-by: Stephen Kelly <stephen.kelly@kdab.com>
Move the cmakeRelativePath function to cmake_functions.

Task-number: QTBUG-32570

Change-Id: I05bbf7084ef8501bf17698f2ecc1cf3d8fd4d460
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@digia.com>
Reviewed-by: Stephen Kelly <stephen.kelly@kdab.com>
Use absolute path in the /usr move workaround if -libdir is specified

Change-Id: I68d087b15839418008db5bf1c0c76ca303245519
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@digia.com>
Reviewed-by: Stephen Kelly <stephen.kelly@kdab.com>