Fixes a couple bugs...
- Pixel font sizes in css would render as point sizes.
- For em font sizes, where the parent size was set and not default, we would
incorrectly convert a pixel value from points to pixels.
We'll always grab the default font size in pixels so we don't keep confusing
things.
Worth noting that gtk css font-size will still behave differently than the
web. Pango interprets font-size differently.
The values can be:
"requested" - the style as requested
"regular" - use a regular full-color icon
"symbolic" - use a symbolic icon
The property defaults to "requested", so no changes should be seen
unless CSS overrides it.
It is also inherited, so that using this CSS
.toolbar { -gtk-icon-style: symbolic; }
is enough to force the whole toolbar to use symbolic icons.
We now support the keywords (like xx-small, medium, larger, smaller...)
and I've changed the default value to be "medium".
This required some shuffling of the "get default font size" code. But
all is well now.
