Prevent int overflow if max_eval_cost is set high.
Fix benchmarking command in test suite.

And update motd to show two new commands.
Adding TODO list.
Fix comment for HEARTBEAT_INTERVAL in options.h
Fix crash when getting file/line for call_out execution.
Generalize get_expliccit_line_number function.

All other variation is using the same underlaying function now.
Test: add command "crasher" for auto crash testing
Test: add test for save_object(int).
Crasher: mulitple missing pop_stack call
Crasher: f_uncompress_file
Crasher: adding type checking in f_ed().
Crasher: dump_prog type checking.
Crasher: localtime, is_daylight_saving crash.
Crasher: f_terminal_color().
Crasher: unique_mapping crasher.
Crasher: save_object.
Crasher: remove_get_char on non-interactive object.
Adding -march=native to gcc.
Adding __DEBUG__ predefine for mudlib.

Allow testsuite tests command run under optimized build.
Bump version 2.24.sunyc4