finally use the fatal error handler

By the way: should you add mmfatl.c to the following list at the beginning of metamath.c:


/* The overall functionality of the modules is as follows:
    metamath.c - Contains main(); executes or calls commands
    mmcmdl.c - Command line interpreter
    mmcmds.c - Extends metamath.c command() to execute SHOW and other
               commands; added after command() became too bloated (still is:)
    mmdata.c - Defines global data structures and manipulates arrays
               with functions similar to BASIC string functions;
               memory management; converts between proof formats
    mmhlpa.c - The help file, part 1.
    mmhlpb.c - The help file, part 2.
    mminou.c - Basic input and output interface
    mmpars.c - Parses the source file
    mmpfas.c - Proof Assistant
    mmunif.c - Unification algorithm for Proof Assistant
    mmveri.c - Proof verifier for source file
    mmvstr.c - BASIC-like string functions
    mmwtex.c - LaTeX/HTML source generation
    mmword.c - File revision utility (for TOOLS> UPDATE) (not generally useful)
*/

metamath / metamath-exe

finally use the fatal error handler #112