Added ICR register for timers.
Removed "Failed to lock..." message.
First pass at a tool to annotate AVR stack backtraces.
RAM based trace buffer for debugging.
Stack overflow detector and first pass at a stack backtrace printer.
Fixed error calculating size of data segment.
Now initializes memory monitor very first thing.
New predicate, is_atom(), and changed laser pulse atom.
size_t is defined in <stddef.h>, not <unistd.h>.
Added #include <stddef.h> so size_t is defined.
Added report_memory().  Not yet tied to a variable.
stop_x_timer() now uses the right register.  Added set_[xyz]_step_interval().
Temporarily Added an abort to trigger_fault so I'll know if it's ever called.
COMMAND_COUNT is now a #define'd constant, not a const size_t.
Added operations to control lasers' timer and pulses.
Split the queues module into queues + engine.  Moved timer ISRs into engine.  Does not yet work in all cases.