add switch description to options.h

/* any switch which is non-be wrt selection floating point code */

/* all switches in this category should start with "NONBE_" */

#define NONBE_FIX_ISM_XOVER_BR

#define NONBE_FIX_ISM_XOVER_BR                          /* FhG: issue 1072: select OSBA coding method depending on number of object and bitrate */

#define NONBE_FIX_1045_ISM_BITRATE_SWITCHING            /* Eri: Difference between ROM/File HRTF in ISM bitrate switching */

#define NONBE_FIX_1067_QUATERNIONSLERP_INACCURACIES     /* Philips: issue 1067: QuaternionSlerp inaccuracies in corner cases */

#define NONBE_FIX_1065_ISM_MD_HANDLE                    /* VA: issue 1065: Allocate only the necessary number of ISM MD decoder handles. */