* saveStyle: retain only known properties in sections[] and normalize their order
* remove styleDigest on import
* shorten detailed status names in updater
* don't autohide update status message
chrome://favicon doesn't indicate an icon is missing in any way, it simply shows a placeholder instead. It also doesn't extrapolate from sub-pages so `example.com` won't have a favicon even if `example.com/subpage` has one.
We don't mention the G+ iframe on CWS stylable only when "Out of process iframes" feature is enabled which can be set manually via chrome://flags/#enable-site-per-process. It's still in development and is known to break some sites, which is why it's not enabled by default.
Chrome can't executeScript on file:// URLs even though we have <all_urls> in manifest.json so on such pages we'll display a warning in the popup. This should only happen when Stylus is [re]enabled/reloaded.
* update state is shown in tooltips that fade out in 10 sec except for .update-problem and .can-update
* when updates are found a filtering option is revealed; when it's checked only entries with updates are shown; when all updates are installed the option automatically hides
* Now that our own pages retrieve the styles directly via getStylesSafe the only 0.001% of cases where code:false would be needed (the browser is starting up with some of the tabs showing our built-in pages like editor or manage) is not worth optimizing for.
* According to CSS4 @document specification the entire URL must match. Stylish-for-Chrome implemented it incorrectly since the very beginning. We detect styles that abuse the bug by finding the sections that would have been applied by Stylish but not by us as we follow the spec. Additionally we'll check for invalid regexps.
* [x] show badge with active styles count
* [x] styles on top in the popup
* Simplify since we use a persistent background page so it's always there for us
