Initial work on media repo restructuring.
Use new mesh paths.
Updated models.
If no parts in submodel, enable all subentities.

I.e. make it easier to define models. If a submodel is added, but no
parts are defined, it's expected that this means that all subentities
should be shown.
Added ability to create a Model from a Mesh.
Updated with new assets.

Some older assets were removed, and there are new ones. One change is
that I've tried to match one model per mesh, instead of cramming
multiple meshes into single models. This ought to make the structure
simpler.
Updated with new material names.
Fix issue with deletion of forward declared class.
Provide deleter for array.

Mainly to satisfy valgrind.
Use infinite paged geometry.

As the world really is infinite, since we don't really know the full
extent of it from the client.
This just means that the paged geometry area will be scrolled.
Fixed issue with incorrect vertex data.

This bug took quite some time to track down.
It appears that on at least gcc 4.8.3 there's some kind of bug which
makes the value assigned be off by one. I.e. if the map is empty, and
we're inserting the first instance, the "size()" method would return
"0", and that's the value we would be inserting. However, for some
reason which might have to do with caching, optimization or out-of-order
execution, the value written is actually the size _after_ the insertion.
So if the map was empty, the first entry would get the value of "1",
which would be the size _after_ the insertion.
And this would of course cause issues later on, with the memcpy writing
beyond the data, thus corrupting the memory, leading to segfaults.
Improved reporting with detailed log messages.
Added checks for invalid values.

This is a band aid though. If the config file contains invalid values
there's not always much we can do.
Use updated material names.
Fixed incorrect removal of invalid particle system
Removed use of Octree scene manager.

Given the nature of the view of the world, where the client only sees
one small part of the world at a time, the octree scene manager adds
overhead without actually contributing much.
Fixed animation reference.
Added extra verbose logging.
Moved data assets to top level "data" directory.

Also put them into "dural" directory. The idea is to have different
directories depending on the world on the server.
Or should we instead put them in a "deeds" directory matched to the
ruleset?
Fixed chicken model.