RF: Rename get_cdf*() functions to get_percentiles*()
RF: Remove most of the DataFrame functions
RF: Add newlines
Merge remote-tracking branch 'origin/cdfs' into cdfs

Conflicts:
	pphelper/tests/test_racemodel.py
	pphelper/utils.py
RF: Add newline
Merge pull request #14 from hoechenberger/cdfs

Cleanup naming, remove some DataFrame functions