Added commands from the webgl branch

[alters-mit]

Command API

New Commands

Command	Description
scale_object_to	Scale the object to the given value. This is only useful if you know the model scale beforehand, which is not always (1, 1, 1). This command is only useful when used with send_scales, because ObjectScales output data will return the actual scale of each object.
send_avatar_ids	Send the IDs of each avatar in the scene.
send_fast_avatars	Send the position and rotation of each avatar in the scene. This is slightly faster than SendAvatars, and FastAvatars compresses much better than Avatars. However, FastAvatars doesn't contain avatar IDs, which makes it harder to use. See: send_avatar_ids which serializes the avatar IDs in the same order as the data in FastAvatars.
send_fast_image_sensors	Send the and rotation of each avatar's camera in the scene. This is slightly faster than SendImageSensors, and FastImageSensors compresses much better than ImageSensors. However, FastImageSensors is missing a lot of information contained in ImageSensors, including avatar IDs, making it harder to use. See: send_avatar_ids which serializes the avatar IDs in the same order as the data in FastImageSensors.
send_fast_transforms	Send FastTransforms output data. This is slightly faster than SendTransforms, and FastTransforms compresses much better than Transforms. However, FastTransforms excludes some data (see output data documentation) and it is also harder to use. See: send_object_ids which serializes the object IDs in the same order as the data in FastTransforms.
send_object_ids	Send the IDs of all Rigidbody objects (models and composite sub-objects) in the scene. The object IDs are sorted.
send_post_process	Send post-processing values.
send_scene	Send streamed scene metadata.
send_models	Send name and URL of each model in the scene.
send_scales	Send Scales data of objects in the scene. The scales are the worldspace scales rather than a factor. Send scale_object_to, not scale_object

Output Data

New Output Data

Output Data	Description
Models	Model names and URLs per object.
ObjectScales	The spatial scale of each object in the scene.
PostProcess	Post-processing values.
Scene	The scene name and URL of the asset bundle.
SystemInfo	System and hardware information.
AvatarIds	The IDs of each avatar in the scene.
FastAvatars	Fast, fixed-length avatar transform data. Use this in conjunction with FastAvatarIds: the order of the IDs matches the order of this data.
FastImageSensors	Fast, fixed-length avatar image sensor transform data. Use this in conjunction with FastAvatarIds: the order of the IDs matches the order of this data.
FastTransforms	None
ObjectIds	The IDs of all Rigidbody objects (models and composite sub-objects) in the scene.

Modified Output Data

Output Data	Modification
Mouse	This is now fixed-length data, meaning that it compresses better and is slightly faster.
Version	This is now fixed-length data, meaning that it compresses better and is slightly faster.

Documentation

New Documentation

Document	Modification
lessons/core_concepts/output_data.md	Added a section for "fast" output data.