Added mixer as a dep
Renamed webmachine endpoint modules so they are easier to find
Factored out common webmachine callbacks to bksw_wm_base
Moved bksw_util:service_available into bksw_wm_base
Reorganized wm callbacks and helpers so it is easier to read
bookshelf 0.2.7
Merge branch 'hh/OC-9567/use-mixer'