Make web client building work with ADVANCED_OPTIMIZATIONS settings

[K1ll3rF0x]

For this, web client code has to be refactored complying with https://developers.google.com/closure/compiler/docs/api-tutorial3 . Three.js does not support advanced optimizations yet, so some hacking might be also required to get this to work properly. The motivation behind this, in addition to better compression, is the dead code removal. We could remove the unused three.js methods from the builded library automatically and reduce the web client library size drastically.