[CMake] control order of custom target as a sub-part of a customized KDE build

[Shawn Rutledge]

Thanks for the suggestions!  I was in a hurry to get something
working, and the first working solution I found was to write a uic
wrapper script which calls uic and then modifies the output.  This
line makes it substitute my wrapper for uic:

set(QT_UIC_EXECUTABLE ${CMAKE_SOURCE_DIR}/tools/uic-wrapper.py)