De-template the ringbuffer.

The parameters are now hardcoded as RepT=char, SampleCountT=unsigned long.

Whilst doing this, I found that player/player_file.cpp was relying on
ringbuffer.hpp to #include <cassert>.  This was erroneous and has been
fixed.
Remove double-newlines.
Merge pull request #59 from UniversityRadioYork/mw-ringbuffer

De-template the ringbuffer