make sure that line chart titles are recreated after filtering. not sure how to create a proper test spec for this.
remove superfluous redraw

render implies redraw, so why this
add test for #742

@deavus (& @eric-poitras), I will not deny that I was overwhelmed by jasmine
tests at first, and still am a bit.

but they're not actually all that hard.  the trick is to come up with something
that fails without the fix applied, and then starts working once the fix is applied
Merge branch 'pr/742'

Conflicts:
	dc.min.js
	dc.min.js.map
	web/docs/index.html
remove extra `fill`

thanks @eric-poitras!!
also test for exactly one title per dot