register_cvar(const name[],const string[],flags = 0,Float:fvalue = 0.0);
@name cvar的名稱
@string cvar的值
@flags裡可放的：
/* Flags for register_cvar() */
#define    FCVAR_ARCHIVE        1    /* set to cause it to be saved to vars.rc */
#define    FCVAR_USERINFO        2    /* changes the client's info string */
#define    FCVAR_SERVER        4    /* notifies players when changed */
#define FCVAR_EXTDLL        8    /* defined by external DLL */
#define FCVAR_CLIENTDLL        16    /* defined by the client dll */
#define FCVAR_PROTECTED        32    /* It's a server cvar, but we don't send the data since it's a password, etc.  Sends 1 if it's not bland/zero, 0 otherwise as value */
#define FCVAR_SPONLY        64    /* This cvar cannot be changed by clients connected to a multiplayer server. */
#define FCVAR_PRINTABLEONLY    128    /* This cvar's string cannot contain unprintable characters ( e.g., used for player name etc ). */
#define FCVAR_UNLOGGED        256    /* If this is a FCVAR_SERVER, don't log changes to the log file / console if we are creating a log */
@fvalue 用途不知道= =