Allow []()*. in html attribute names #725

[Runinho]

Fix issue #725
Allow []()*. in Attribute names with values.
Allow #* in Attribute names.

[NEO97online]

LGTM, is anything holding this up? Would be great for angular2.

[dblessing]

Thanks @Runinho. Instead of the specs all we need is some examples in spec/visual/samples/html that show this works. I appreciate the sentiment in adding tests, though.

[pyrmont]

@Runinho I had two apologies:

1. I'm sorry but I've force pushed to your branch. I've rebased this PR against the current version of master and fixed a couple of things to reflect changes since your original submission.

2. More generally, I'm sorry it's taken such a long time to get to this. Thank you for taking the time to prepare the request, I think we should be good to merge in very soon!