Note ideas for component mostly from retina.js
Don't ignore dist directory
1.0.2
Replace the src attribute instead of recreating element

Letting React manage the src attribute meant that if there was a retina
image, the old non-retina element would be destroyed and a new retina
one created causing a noticable blink. Changing the src attribute
directly avoids this.
1.0.3
Unnecessary comment
If picture names aren't same, just pass in array of srcs
Merge branch 'master' into gh-pages
New release