AddConstEx

***********************************************
** add a member of enum - a symbolic constant
        arguments:      enum_id - id of enum
                        name    - name of symbolic constant. Must be unique
                                  in the program.
                        value   - value of symbolic constant.
                        bmask   - bitmask of the constant
                                  ordinary enums accept only -1 as a bitmask
                                  all bits set in value should be set in bmask too
        returns:        0-ok, otherwise error code:
#define CONST_ERROR_NAME  1     // already have member with this name (bad name)
#define CONST_ERROR_VALUE 2     // already have member with this value
#define CONST_ERROR_ENUM  3     // bad enum id
#define CONST_ERROR_MASK  4     // bad bmask
#define CONST_ERROR_ILLV  5     // bad bmask and value combination (~bmask & value != 0)

long AddConstEx(long enum_id,string name,long value,long bmask);