Plasma QML apidox script works recursively now

This script now takes a base path, walks into it and generates a
flat list of html files, just like for the plasma components
previously.

The script should be run from kde-runtime/plasma/declarativeimports/ like so:

qmlapigenerator.py -v "Plasma Quick master" \
-t /home/sebas/kdesvn/src/apidox/data \
-i /home/sebas/kdesvn/src/kde-runtime/plasma/declarativeimports/ \
-o out/