Merge branch 'master' of git://github.com/emolch/pyrocko
possibility to sort traces by channel first
open waveform files and directories menu entries
Use markdown to create pretty docs without the need of writing html
code.
Revert "Use markdown to create pretty docs without the need of writing html"

This reverts commit b011dbd50a42e14516de7406fccc7e03f6dfdbd9.
Extended/corrected documentation.
Merge branch 'master' of git://github.com/emolch/pyrocko
Added possibility to create markdown help
If html is in self.__doc__ this will be used.
removed print statement
Made markdown optional
added gf store
New menu item: open station files...
added fomosto/gf stuff
use potint interpolated v and u values also for homogenoeus layers
fixed problem with ray drawing at zero distance
added to_scanlines() method
remove trailing spaces at linends in model output
added function to return model in nd format as string
improved accuracy, reliability and speed
usgs catalog now reads geojson feed