Refactoring of class names

- Removed any reference to r3 in class names.
- Added prefix uv for class names.
- Using d3 "classed" selection instead of "attr" to avoid any overwriting
  of exisiting class names.
- Using hyphen instead of underscore in class names.
- fixed bug with mouseover event on area chart.
Fixed missing reference of class name
- Refactoring of class names across src files
- Standardization of references to library

Merge branch 'master' of https://github.com/priyankadudani/uv

Conflicts:
	src/gfx/area.js
	src/gfx/bar.js
	src/gfx/donut.js
	src/gfx/graph.js
	src/gfx/line.js
	src/gfx/percent_area.js
	src/gfx/percent_bar.js
	src/gfx/pie.js
	src/gfx/stacked_area.js
	src/gfx/stacked_bar.js
	src/gfx/stepup_bar.js
	src/gfx/waterfall.js
	src/util/effects.js
	test/d3/d3sample_1.html