Add VERBOSE and EXTRA_VERBOSE options in config.landslide.
Add PRINT_DATA_RACES option for students to enable the experimental feature in config.landslide
add verify_numeric calls for config options from previous commits
Add TABULAR_TRACE option and some logic that prints, for now, utter nonsense when it's enabled.
Separate stack trace (and within function) into own new file, stack.c.
fix Q_INSERT_TAIL buge
Pass around stack traces as their own structs instead of preformatted strings.
print_stack_frame print frames in colour
Add print_eip() and convert users of old symtable_lookup() to use it
Print stack traces in html.
Switch to FOUND_A_BUG() everywhere, passing reasons into found_a_bug, and print reasons in tabular traces too.
add user mutex unlock as a PP
Add estimate_computed flag so we can output estimates in html traces
Specially compute SS estimates in found_a_bug to output them in html traces.
Fix within_function to use stack_trace as a helper, and fix #24 re lmm_remove_free. Lots of apparent speedup from the latter.
decided not to reorg symtable_lookup_data interface after all