Allow lower case tagName

If this is used to match inline SVG, tagName will be reported in lower case. By forcing tagName to upper case, we get support for SVG anchors.
Compiled code
Revert "Compiled code"

This reverts commit 5b8680fc9b40195aca45b49b9062ec58e0f4c64f.
Merge pull request #37 from stianlik/patch-1

Allow lower case tagName