Implement map reverb effect entities

I did not really test that it works on map using these entities yet
but it works on regular maps.
The reverb can be added to func_static the same way colorgrading is
the keys are:
* reverbEffect <argument to /testReverb>
* reverbDistance <float>
Also reverbEffect can be used on the worldspawn for a global effect.
Audio: remove leftover debug
Fix team-specific /editbind (missing a space).
Correctly quote console comands which are passed to the server.

This fixes commands such as /vsay_team incoming "Enemy incoming!"
Don't unnecessarily quote escaped strings.
Fix compilation in MSVC 2013: it doesn't support constexpr and unicode literals
Fix escaping of empty strings.
String escaping: fully handle white space, short-circuit empty string.
Escaping: always wrap strings containing // and /* in "".
Cvar: add Range, range hecked cvars
Audio: Make intensity cvars for doppler and reverb

Also used range cvars for volumes.
Update the option menus for the doppler/reverb changes
Add the 'reverbIntensity' key for the worldspawn and func_static to have saner default reverb presets
Fix reverbIntensity defaulting to 0 on the worldspawn
Actually fix reverbIntensity defaulting to 0 on the worldspawn
Fix another possible NULL deref.
Tighten up packet entity parsing & emission.

This fixes a theoretical NULL dereference and some theoretical OOB accesses.
Audio: small fixes to /testReverb and default reverb intensity
Debian packaging updates.