master library file and mixin creation

demo stylus selector using tooltip mixin for basic tooltip styling
basic tooltip display functionality

hidden normally, visible on hover/focus
basic tooltip positioning

positioned directly above target element.
does not take up space in the page flow
display: inline-block

defaulting to display: inline-block gives better regular usage of the
mixin
tooltip parameter type check
prevent tooltip from going newline

targets smaller in width than tooltips were making tooltips newline
center tooltip over target

include cross-browser transform mixin
ie8 support dropped.  ie9+ working as expecting