ResponsiveImagesCG/picture-element — pull request #112 by zcorpan (2014-02-21 11:10:09+00:00)
Title: Parse srcset attribute more like original srcset. Fixes #97

This change has a number of implications:

* CSS escapes are no longer supported.
* The whole attribute is not ignored if one entry is invalid (better future compat).
* Only "x" is supported, not "dppx" etc.
* HTML rules are used instead of CSS rules for parsing the numbers.