Refactoring of the CMake files: Only little changes have been made so far, because it is way more complicated than I thought.
Right now the following things have been done:

- static lib for queuemanager
- static lib for advancedrename
- one INCLUDE_DIRECTORIES in the main CMakeLists.txt file
- removed duplicate entries

We should do the refactoring in small amounts, every now and then we can fix
some problems, so that one day we are able to build other projects like the
unit tests and the themedesigner without recompiling the whole digiKam code
again.

Gilles, can you test this patch with Windows and Mac?