Revert "use another way to retrieve a PMF hash"

This reverts commit 9918130fae12e6368bea138776dae0177dec9870.
put pmf in a preprocessor clause (non-gcc path will compile but won't work at runtime)
fix EventbatchHandler::FeatureMoved
update man-page
link spring:// scheme under most linux enviroments (spring from browser \o/)