VS 2017 was complaining about truncating the value.

added more MemTrackable types
optimized memory usage of LLTrace some more

changed claimMem and disclaimMem behavior to not pass through argument
added more mem tracking stats to floater_stats

image memory utilization now always non-negative

renamed "current" to "primary" when referring to accumulators

removed bad assert
fixed precision issues during int->unsigned int conversions and vice
versa

added unit tests for lltrace

made getPrimaryAccumulator return a reference since it was an
always non-null pointer
changed unit conversion to perform lazy division in order to avoid truncation
of timer values

continued conversion to units system
made units perform type promotion correctly and preserve type in arithmetic
e.g. can now do LLVector3 in units
added typedefs for remaining common unit types, including implicits

moved object cache sampling code so that it actually gets executed
default values for stats are NaN instead of 0 in many cases

fixed some lltrace logic errors
more consistent syncing of timestamps of sample values in recording stack
selection of primary buffers was completely incorrect
assignment of recordings got wrong play state due to implicit
operator = defined in base class
fixed asset stats only working up to the first send

pulled swap() out of ui time block
cleaned up internal lltrace dependencies, factored out common accumulator definitions