Fixed the Makefile

Not knowing the Makefile system very well ( and being used to CMake
for a long time, I had breaked the Makefile for a few people. Dirk
came to the rescue, and asked me to not edit the makefile manually.

This commit simply reverts the mess that I had done earlier. :)

Signed-off-by: Tomaz Canabrava <tcanabrava@kde.org>