Extracted scene creating to methods.

Will be filling these methods now.

Signed-off-by: Ken Hoover <ken.hoover@mail.utoronto.ca>
Added table manager.

Essentially a pool for tables, but since they're not really objects, can
just use the array.

Signed-off-by: Ken Hoover <ken.hoover@mail.utoronto.ca>
Added GroupManager.

Signed-off-by: Ken Hoover <ken.hoover@mail.utoronto.ca>