Fix AssertFatal/TORQUE_UNUSED are not optimized on release build causing performance problems.

http://cnicholson.net/2009/02/stupid-c-tricks-adventures-in-assert/
> "Both gcc and MSVC are smart enough to optimize out the evaluation of x, but only if they can determine if  there are no side effects associated with the evaluation.  Unfortunately, this can only be done if the body of x is known entirely to the compiler.  If x is a function call to another module MSVC can still make it go away with Link-Time Code Generation (via cross-module inlining), but poor gcc is dead in the water and emits the call.  Either way, we’re relying on compiler and linker optimizations to make this code go away."
Merge pull request #675 from BeamNG/fix_assertfatal_release_performance

Fix assertfatal/TORQUE_UNUSED release performance