Update encoder

[devongovett]

• Use latest brotli C code
• Only build encoder, since we are using a JS decoder now.
• Remove pako dependency for decompressing the memory file. Decompress using Brotli itself!
• Adds additional options to compress function (backward compatible to old boolean option for text vs binary).
• Remove dependency on brfs and a custom browserify transform by storing files as base64 JS modules that can be required. This is what brfs transformed it to anyway.
• Add missing dependency on base64-js: undeclared non-core dependency #9.

[devongovett]

Oh also, the encoder is less than half the size now thanks to new emscripten options!