Adds a test to codify what I think greasemonkey scripts expect from
their scope chains. Particularly that they can:
1. access the global `window` object
2. access all of the attributes of the global window object as global
objects themselves
3. see any changes the page made to the global scope
4. write to attributes of `window` and have those attributes, and changes
to existing attributes, accessable via global scope
5. do number 4 without breaking the pages expectations, that is what
`unsafeWindow` is for
There are some other points about greasemonkey scripts' environment that
I believe to be true but am not testing in this change:
* changes a page makes to `window` _after_ a greasemonkey script is
injected will still be visible to the script if it cares to check and
it hasn't already shadowed them
* said changes will not overwrite changes that the greasemonkey script
has made.
The greasemonkey `@match` directive is used to match urls against
chromium url patterns (as opposed to `@include` which treats its
argument as a glob expression). I was using fnmatch for both here
because I am lazy and knew someone else was going to implement chromium
url patterns for me eventually. Now it is done and I should switch to
using them instead. The most common failing case that this will fix is
something matching on `*://*.domain.com/*` because it wouldn't match
the url with no subdomain.
This codepath is only used on webengine 5.7.1 and webkit backends.
Like the spec says, if a value for the @include or @exclude rules starts
and ends with a '/' it should be parsed as a regular expression.
Technically a ECMAScript syntax regular expression, but I am not sure of
the differences and I assume they are far fewer than the similarities.
One that I did see mentioned was that javascript RegExp doesn't support
unicode. Although it apparently does support a 'u' flag now.
Note that code will only be ran for QtWebkit and QWebEngine < 5.8
we rely on the builtin support for metadata it QWebEngine for most
things greasemonkey related. Sadly it seems that they missed the regex
requirement too. I've opened a ticket to track that https://bugreports.qt.io/browse/QTBUG-65484
