tagging-tokens attribute not working, nor is default comma token

[pderksen]

tagging-tokens isn't working as indicated at https://github.com/angular-ui/ui-select/wiki/ui-select.

Run /examples/demo-tagging.html to see behavior.

The 4th example has specific tagging-tokens (tagging-tokens="SPACE|,|/"), but throws an error if you use any of them.

Also, when tagging-tokens isn't specified the defaults should be Enter and comma (,), but comma doesn't work in the top 3 examples.

I started some work on this in PR #474 but haven't fixed it yet.

[brianfeister]

Thanks @pderksen, I ended up fixing it en masse with some other issues. fc93c66

[pderksen]

Many thanks @brianfeister !

From the same PR is this trimming issue:
https://github.com/pderksen/ui-select/commit/3a79a386b7801370157881ff933ac7a59f9a7565

But PR #447 actually beat me to it.