Only skip a character when it actually is the comma.
Remove all trailing commas in url. Also skip to next candidate if that made url empty.
Support parentheses with commas in them in descriptors. Fixes #166
Make the srcset parser aware of 'h' descriptor. Fixes #176
Merge pull request #177 from zcorpan/fix-166

Fix #166
Merge pull request #178 from zcorpan/fix-176

Make the srcset parser aware of 'h' descriptor. Fixes #176