pdDebug: allow action caching before class is formally initialized

PD's load process is complex.  Many functions rely on other functions
for various initialization parameters, so the process is a bit like a
spider web instead of an orderly queue.  As such. the main pdDebug
instance isn't formally initialized until quite far into the load
process, to ensure that all the program pieces it relies on are
available prior to logging actions.

This complicates matters, because there are some things I want to know
about (like monitor detection) that happen long before formal
initialization.  As such, the class has been updated to cache message it
receives prior to being initialized.  When it finally gets initialized,
it will write all cached messages to the log (with their original
timestamps).

Also, minor formatting cleanup in this commit.
pdDebug: log LoadMessage() input

Also, change central Message() interface so that we log messages prior
to translation.
pdVoronoi: misc optimizations

Doubles are faster than Singles for in-line processing, but as this
function moves tons of floating-point values as parameters and returns,
the cache thrashing outweighs the in-line performance.  On a 10
megapixel image, switching to Singles shaves 3-4% off the total
run-time.
pdDebug: more fine-grained message types
pdDebug: add RAM updates

These can be requested on-demand, but if pdDebug goes 20 events without
receiving a RAM update request, it will automatically provide an update.

Delta from last check and max session usage is also tracked.
pdDebug: add processor call logging