PREDEFINES
                                  ~~~~~~~~~~
                              (Created 93.07.17)

This file lists predefined identifiers that may be visible at compile time
of LPC objects.  Mudlib developers are encouraged to refer to this file and
develop their code according.

The following identifiers are ALWAYS defined.

    LPC3            - identifies the driver as LPMud 3.x derived
    MUDOS           - identifies this variant of LPMud as MudOS
    USE_EUID        - identifies the driver as using the uid/euid system


The following identifiers are ALWAYS defined; these are strings unless
otherwise noted.

    SAVE_EXTENSION  - save file extension for use with save_object() and
                      restore_object(); see "options.h"
    __ARCH__        - architecture of the machine that compiled the gamedriver;
                      replaces MUDOS_ARCH
    __VERSION__     - current version of the MudOS driver; replaces
                      MUDOS_VERSION and VERSION
    __PORT__        - port that gamedriver is accepting user logins from
                      (integer); replaces MUDOS_PORT
    __DIR__         - names the directory containing the file currently
                      being compiled; replaces MUDOS_DIR


The following identifiers are sometimes defined; these are string.

    __COMPILER__            - this is the compiler used; $(CC) from Makefile
    __COMPILER_VERSION__    - this is compiler dependent (depends on a
                              NON-ANSI predefined symbol)
    __OPTIMIZATION__        - these are the optimizations flags from Makefile
    __MUD_NAME__            - this is your mud's "name" as specified in your
                              runtime configuration file


The following identifiers may be defined.

    HAS_SOCKETS     - defined if socket efuns are enabled
    HAS_SHADOWS     - defined if NO_SHADOWS is #undef'd
    HAS_DEBUGMALLOC - defined if debugmalloc() efun enabled
    HAS_MATH        - defined if math efuns for float support are enabled
    HAS_MATRIX      - defined if the 3D graphics efuns are enabled
    HAS_ED          - defined if built-in line editor (ed() efun) is enabled
    HAS_PRINTF      - defined if printf() and sprintf() efuns are available
    HAS_PRIVS       - defined if object privileges are enabled
    HAS_EACH        - defined if the each() efun is enabled
    HAS_CACHE_STATS - defined if call_other (apply_low) cache stats are enabled
    HAS_OPCPROF     - defined if opcprof() efun is enabled
    HAS_DEBUG_LEVEL - defined if DEBUG_MACRO set in Makefile
    HAS_RUSAGE      - defined if the host machine has getrusage() syscall
                      (or something similar)