rebuild library
collection of minor bug fixes and changes

The changes are as follows:
* Allow user to specify previously forbidden key in Sprite config
	The non-existant distance, speed, rate, posAngle, motAngle, accAngle
	were previously forbidden in Sprite construction, because they depend
	upon the existance of the primary values. However, the user can now
	specify them, and internally they are moved to a different object
	which is feed to the set method only after all primary values
	have been properly set.
* Make adjustments to 'SPRING' boundary action
	hopefully these adjustments produce the desired result, this
	boundary action is still experimental and untested.
* Added default `index` and `start` attributes to env.ANICYCLE_DEFAULT_CONFIG
* Set `#gh-main` tabIndex to 0, so that it can listen for key-stroke events
* Added @panelFontSize to style.less
	It is used to calculate the font-size in classes `.gh-a` and `.gh-p`