Lazy instead of greedy matching on the SRC and HREF regex

If the <link> tag has the href as the first attribute, the RE_HREF regex will match all following attributes as well. When we switch to lazy matching it will only match the href itself. Same change for the RE_SRC regex.

Example: `<link href="top.css" rel="stylesheet" inline />` will match `href="top.css" rel="stylesheet"` with greedy matching and `href="top.css"` with lazy matching.
Merge pull request #7 from matiaslarsson/patch-1

Lazy instead of greedy matching on the SRC and HREF regex