Glow effect on input:focus.

Icons for input:valid, input:invalid
New watcher for [data-scroll-to]

Will scrollIntoView() on the element matching its value/selector
More error_page template updates.

Use HOME instead of URL.

Offer a list of suggested actions, including link to HOME, button to focus and scroll
to tag search, report a bug.
Invert checks for setting $this->url

if(is_string()) -> use $url
else use script calculated version.
Updated error page title & add another newline
Merge branch 'issue_26' into dev
Resolve issue #26 (Need 404 pages)

This commit to close issue only adds title to search button