playback cannot be found for some combinations of OS and playback file
* fixes problem introducted (by me) in pull 175
Merge pull request #180 from jmoody/0.9.x-playback-broken-by-pull-175

playback cannot be found for some combinations of OS and playback file
Merge branch '0.9.x' into 0.9.x-playback-verbose-reporting

Conflicts:
	calabash-cucumber/lib/calabash-cucumber/core.rb
added comment for the interpolate function - never called?
made the playback search algorithm easier to understand
Merge branch '0.9.x-playback-verbose-reporting' into 0.9.x-riseup-master

Conflicts:
	calabash-cucumber/lib/calabash-cucumber/core.rb
record_end saves to PLAYBACK_DIR or ./features/playback and the default playback search directory is changed from ./ to ./features/playback