Build fixes for in-tree and 32/64-bit

Build fixes for in-tree and 32/64-bit

Expand the comments in mtrace-ctl.c to better explain how to use
this tracing controller.  The new docs assume the SO is built
and installed.

Build fixed for trace_run.c

Additional build pedantry to let trace_run.c be built with more
warnings/errors turned on.

Build/install trace_run and trace2dat

trace2dat takes dump files from mtrace-ctl.so and turns them into
mmap'able data files for trace_run, which "plays back" the logged
calls.

32-bit compatibility

Redesign tcache macros to account for differences between 64 and
32 bit systems.