Surface|World: Cleanup
Sector|World: Cleanup
Plane|World: Cleanup
Refactor|World: Moved global var ddMapTime into de::World
BSP Builder: Ensure 'extra' meshes contain only half-edges for map lines

Previously an extra mesh was generated for all so-called discordant
edge geometries. We only ever draw wall geometries for these edges
so we can omit half-edges produced by splitting the subspace.
Sector|World|Client: Sector now manages rough area approximation updates internally
Sector|World|Client: Sector now manages axis-aligned bounding box updates internally
Sector|World: Sector now manages sound emitter origin updates internally
Map Renderer|Client: Cleanup
BspLeaf|World: The parent of a BSP leaf is the sector to which it is assigned

Note that the parent sector is that which defines the "physical"
properties of the BSP leaf (i.e., the sector whose plane's define
the physical floor and ceiling heights for the leaf).
BspLeaf|World: BspLeaf API now distinguishes between "physical" and "visual" planes

Updated the map renderer to use the logically correct API method.
Note that at present both physical and visual map to the same plane.
Sector: Added Sector::Cluster

Adjacent BSP leafs in the sector (i.e., those which share one or more
common edge) are grouped into "clusters". A cluster is never empty and
will always contain at least one BSP leaf.

Note that at present no clustering actually occurs and all BSP leafs
for a sector will be added to a single cluster.
BspLeaf|World: Attribute BspLeafs to the Sector::Cluster they are a part of

Rather than reference a sector directly, BSP leafs are attributed to
a sector cluster which in turn provides access to the sector.
BspLeaf|Sector|World: BspLeaf obtains plane references from the attributed sector cluster
Debug|Map|World: Cleanup
Refactor|Sector|Map|World: Moved algorithm for fixing missing line side materials to Sector
Map|World: Cleanup
Sector|World: Each Sector::Cluster has its own axis-aligned bounding box

In the case of a cluster defined by a single BSP leaf the bounds of
the leaf's geometry will be used directly.
Sector|World: Fix typos
Fixed: Warning about ineffective use of "const" in return value