Update Stylus.tmLanguage

Got sick of things looking weird in my stylus code, so I fixed some things.

In this
```css
.herp[name=pie][href]
```
`[]` Square braces are given `meta.brace.square` scope
`name` is given `entity.other.attribute-name.stylus`
`=` is given `meta.delimiter.stylus`
`pie` is given `string.quoted.stylus`

Fixed issues in
```css
display: table-cell
vertical-align: top
float: left
clear: right
```
Where `table-cell/table-row/table` would be styled to the tag name and not as a property-value, same with `top/bottom/left/right` for vertical-align, float and clear.

Renamed functions to `meta.function-call.stylus` as the regex selects actual calls to the function (though technically definition of a function is the same syntax).

UPDATE:
Also fixes #17