Add visvis calculation and cgame trap.

Visvis is similar to vis, but while vis indicates if there is a direct
line of sight between two clusters, visvis indicates that there is an
indirect line of sight (i.e. there is a common point from where there are
lines of sight to both clusters).

The computation of visvis used here is not geometrically exact, but if
it differs from the definition given above, it's always the case that
it may indicate an indirect invisibility where none exists, so it is
still safe to use it for culling. In practise the differences are not
important.
Move radar updating to the client and filter blips not in visvis range.

This should allow the radar to sense around corners, but filter out
rooms on a different level of the map. How well this works depends
on the quality of the vis data.
Add detection of player inactivity.
Don't fail if the pipe file is present but no running instance.

Requires lsof.
Client side range markers.

The client just draws the range markers as part of the corresponding
buildable. This means that no extra entities have to be communicated
from server to client for the range markers.

The downside is that range markers can be culled with their buildable,
but since buildables in radar range are never culled, this is hopefully
acceptable.
Fade out range markers softly at 90% radar range.
Fix gpu vertex skinning for mac drivers
Apparently these operations are not equivalent on mac.
Who knew?
Set rgbGen on "blend diffuseMap" in vanilla renderer so we do vertex lighting on our models
Calculate vertex normals for md5 models in vanilla renderer
This fixes vertex lighting for md5 models
Fail during build configuration if libwebp < 0.2.0 is found.
Update changelog.
Link against libopenal rather than dlopen it. (Fixes a missing dep.)
Merge Info.Plist's together

Info.Plist for x86 and x86_64 are now identical due to removal of arch
string in executable names.
Correct minor capitalisation error
Build with voip even with BUILD_CLIENT is disabled
Move some #defines affecting function visibility (C library etc.).
Specifically check whether SIGWINCH is defined where used.
Default binding for /messagemodec.
Ignore kdevelop4 project files
Remove bass libraries

Bass libraries are no longer used and have a potentially problematic
licence.