Optimization of code size, remove large amounts of dead code linker can't kill

[trevorlinton]

Specifically:

1. Most of the loader / platform code can be killed. ( ??)
2. Backtiling? This is somewhat unnecessary. (est savings 800KB)
3. WTF cleanup (est savings 0.8MB)
4. Remove curl all together and use lightweight callbacks to XHR and http node module? (est savings 0.4MB)
5. Reduce freetype to only LCD 'light' renderer, not all of them. (est savings 0.3MB)
6. Package fonts more efficiently than gigantic 0-255 Uint8 array? (est savings 0.8MB)
7. Linker optimizations LTO? ( ?? )
8. Use a closure compiler / minimizer as post build action (est savings 2-3 MB)

This should take it down from ~21MB to ~15MB uncompressed (~3MB Gzipped by server)