Small optimizations in defineFont
Make metrics available in Font instances, and add per-character advance values

Plus some small somewhat-related fixes.
Merge pull request #1369 from tschneidereit/nat

Make font metrics available in Font instances
Print combined run time after finishing all shell unit tests
Ignore invalid gradients instead of drawing fully opaque white

I'm not entirely sure why I thought this was the correct behavior in the first place. Flash just ignores the `beginGradientFill`/`lineGradientStyle` call and continues using whatever was specified before.
Fix bugs in Graphics#lineGradientStyle and add unit test
Implement emitting line gradient definitions in defineShape
Implement rendering line gradients
Merge pull request #1370 from tschneidereit/nat

Support for line gradients in embedded shapes and via Graphics API commands
Refactors ExternalInterface
Merge branch 'nat' of github.com:mozilla/shumway into nat
First stab at clipping.
Merge branch 'nat' of https://github.com/mozilla/shumway into nat
Fix dissassembler and AVM2 shell.
Perform a dirty local analysis to prevent the insertion of unnecessary PHI nodes.

This should speed things up quite a bit, at least in terms of compilation time.
Take care of hasNext2 since it touches locals.
Cleaning up.
More cleanup.
Don't self host push and pop.

This can get us huge boosts in speed and we should do this for all natives. Startup time will also improve if we go through all of these and route them to JS versions.
Update refs.