revert back to before padding was implemented

previous commits introduced new bugs, so we’ve reverted back to
820a745b0c72931dd05d6741118e4a574328e2fb
reverting conflicts

Merge branch 'master' of https://github.com/vijithassar/d3textwrap. At
this point the bounds argument *must* be a rect, something is getting
wacked out with the simpler object approach.