Crossbars, median lines, and other refactoring

tg.js
* Added getLineAngle (moved from tg.Glyph)
* Added getStrokeOutline (moved from tg.Glyph)
* Added getIntersection

tg.Glyph.js
* Added shortcut to model
* Fixed documentation
* Made getPoint an instance method
* Removed methods that were moved to tg.Font
* Updated logic as per strokes now being objects
* Separated crossbar logic
* Changed the way crossbars are calculated, now they are always on the median line (Will make them more configurable later)

tg.Font.js
* Made strokes more descriptive
* Changed default value for width param to 0.125
* Removed step property from params (it can be calculated)
* Moved transformPoint hooks into params
* Removed crossbarHeight param
* Added meanLine param
* Moved transform point back to tg.Font
* Added resetParams method
* Removed getParamsStep method

index.html
* Added reset button