Allow for non-standard Assert-enabling macro

[Graham Pentheny]

Currently rcAssert is disabled if NDEBUG is defined. It's often useful, however, to have non-debug builds that have asserts enabled.

To allow for this kind of flexibility in usage, rcAssert should be defined based on a Recast-specific preprocessor declaration, rather than a standardized one like this. Something like RC_ENABLE_ASSERTS

recastnavigation/Recast/Include/RecastAssert.h

Lines 25 to 30 in b51925b

 #ifdef NDEBUG 
  
 // From http://cnicholson.net/2009/02/stupid-c-tricks-adventures-in-assert/ 
 #	define rcAssert(x) do { (void)sizeof(x); } while((void)(__LINE__==-1),false) 
  
 #else