Cleanup: Removed "notarget" from conhelp.txt

There is no such cheat code in any of the supported games.
Documentation: Removed notarget.ame

There is no such command in any of the supported games.
External|SDK: Updated libassimp to version 3.1.1 (with deng patches)
Unix|qmake: Added build option "deng_distcc"

Distributed gcc/clang builds.
SDK|Fixed|OS X: SDK deployment issues

Fixed a number of issues with the new packages and OS X rpaths.

Todo: The "net.dengine" packages should be deployed to the SDK dir.
Merge branch 'master' into gl2-models
Cleanup
Qt|qmake: Minimum required version of Qt is now 4.8
Model Renderer|GL: Diffuse and specular light in model shader