Made photosets responsive

Used Tumblr's {Photoset} tag to render photosets at 100% of parent
width, and a few lines of JS to make mobile browsers pay attention
(natively, they display the photoset at the maximum possible size and
not 100% of the viewport).
Merge pull request #27 from edadams/master

Made photosets responsive
Removing resize JS function
Merge remote-tracking branch 'upstream/master'