move npm scripts to use "serve"/"open"
ignore npm-debug.log
no longer need fiddle.js
add initial snap.plugins with d3_mouse
add #mouse_point
add .isPointInsideBox, .offsetBox and .normDeg
add <.rotator> and #rotate
add #nearest_rotation
add #should_i_rotate
add #box
refactor drag(..start|end) to include rotate