Prefer direct member access than type_id()
Element::removeAttribute* does not need to throw
Merge pull request #2905 from brunoabinader/element-removeattr-no-throw

Element::removeAttribute* does not need to throw
Ignore spaces in base64 data URLs. Fix #1268.
fixup! Ignore spaces in base64 data URLs. Fix #1268.
Merge pull request #2908 from SimonSapin/base64-space

Ignore spaces in base64 data URLs. Fix #1268.
Merge pull request #2906 from brunoabinader/node-typeid-fix

Prefer direct member access than type_id() in Node self.type_id calls
Implement kerning support for linux/android. Improves some wikipedia issues (#2554).
Add --enable-tree-rust to configure to build in-tree rust compiler
Merge pull request #2884 from glennw/linux-kerning

Implement kerning support for linux/android.
Add charset declarations to non-ASCII tests
Modify Linux travis config to run content and cpu ref tests.
Port attribute name to use atom.
Merge pull request #2903 from ChrisParis/cfg_tree_rust

Add --enable-tree-rust to configure to build in-tree rust compiler
Add support for showing debug borders

This can help debug issues with the compositor and show when a page is
creating layers.
Add basic support for web fonts. Synchronous loading only
for now, and only deals with TTF format fonts.

For an example, try loading http://icons.marekventur.de
Fix missing license header in new file.
Address review comments.
Don't rely on font hint for format detection. Handle parsing comma
separated format hints. Fix oversight in mac code dealing with
creating web fonts from memory.
Update font face to new url parser.