Update to walk.js v1.12

Refactored code (walk.js reduced to < 25%, walkInterface.js reduced to < 14%)
Added walk.js to defaultScripts.js (suggestion)
New asymmetrical animations for flying and female standing animations
Updated setSkeletonOffset as per Interface / JS specification change (now specifying offsets in avatar frame, not global as before)
Smoothed out transitions
Implemented overlapping transitions (i.e. transitioning from a transition)
Frame by frame blending of different flying animations (fwd, up, down) depending on orientation of direction of travel
lets fix the footstep sounds... tell me what isn't working.