since google won't create support library for PreferenceFragment,
someone else did. Had to change some minor stuff to make it work in FWM
(i didn't want to add another project), so making a single commit for
doing these changes and adding the library from
https://github.com/kolavar/android-support-v4-preferencefragment
replaced PreferenceActivity with PreferenceFragment. trying to figure out some really peculiar performance issues