Would appreciate some help with a better image, I did my best.  Don't
know if it was optimal resizing.

…th an hd example

Conflicts:
	README.md

tested this example and the the div implementation of picturefill on an
iphone 4 with -webkit- prefixes and a lower min-device-pixel ratio
(1.5).  leaving out the prefixes to be more future friendly in the
readme

Conflicts:
	index.html

Any classes applied to a source  element served to the user are applied
to the displayed image.  This only occurs on inital page load, however.
Two issues needed to be considered to make this happen as @beep
proposed: 1) should applied css classes by preserved when resizing from
one breakpoint image to another?  and 2) how should the unused data
source list classes be ignored as to not accidently affect page
rendering?.   I resolved both by making the following assumption: the
main use case for picturefill is to serve the correct image once.
Someone at an An Event Apart said that the only people that regularly
resize browser windows to test for responsiveness are developers.  Even
so, one can easily preserve css classes between breakpoints by
duplicating them.