Add GUI features

[madblade]

(To whomever it matters to)

Possible future milestones:

• Add user-controlled graphical settings (mouse sensitivity, water reflection, shadow maps, etc.)

• Add help menu

• Locale detection

• Raycast helper (wireframe box showing to indicate the user where a block addition would occur)

• Put the camera closer to the head, and perform a reversed-raycast to adjust the camera position (prevent the camera from going inside the terrain geometry). Perf: only raycast on the closest 4 chunks.

• Camera lock / camera switch target (important for ease of use on mobile devices)

• Chat (prototypes in client/app/modules/chat)

• Console to send commands to the server

• Wire in and expose random seed / flymode / op state

• Sun position synchronization

• Node.js CLI commands(?) (really not a priority)

• WebAudio module (prototypes in client/engine/audio)

• Inventory and crafting system(?) Not entirely sure where this would belong. Probably in modules. This should be done together with entity life/death depending on user needs.