Closes #4609

Closes #4585

See: https://drafts.csswg.org/css-grid/#grid-shorthand

As described in http://caniuse.com/#feat=user-select-none and https://developer.mozilla.org/en-US/docs/Web/CSS/user-select

Closes #4340

Closes #4325

Closes #4325

Add gutters properties (grid-gap, grid-column-gap and grid-row-gap):
https://www.w3.org/TR/css-grid-1/#gutters

Take advantage to add some missing keywors:
* grid and inline-grid: https://www.w3.org/TR/css-grid-1/#grid-containers
* dense: https://www.w3.org/TR/css-grid-1/#grid-auto-flow-property

It's been a while since the list of properties has been updated:
https://drafts.csswg.org/css-grid/#property-index

Issue #3625

Closes #3585

Closes #3475

Closes #3470

Closes #3417

Closes #3336

Issue #3253

Closes #3244

Issue #3164

[attr, calc, counter, counters, linear-gradient, matrix, matrix3d,
perspective, radial-gradient, repeating-linear-gradient,
repeating-radial-gradient, rotate, rotate3d, rotateX, rotateY, rotateZ,
scale, scale3d, scaleX, scaleY, scaleZ, skew, skewX, skewY, symbols,
translate, translate3d, translateX, translateY, translateZ, var]

And don't call delete on the state object.

Issue #3084

Add support for @counter-style blocks by making them and @font-face
blocks match a new "restricted_atBlock" state based on "font_face"

Teach it about @document in a more general way than my first attempt,
and also do @supports the same, by treating both them and @media as
atBlocks with shared word parsing