Re #8056. Making internal helper methods private.
Re #8056. Making one helper function inline.
Re #8056. Inlined a number of methods for performance.

These methods were previously (implicitly) inlined. Moving their definitions
out to the cpp had a negative impact on performance. I've moved the
definitions back to the header file, but now they are explicitly inlined
and defined outside of the class declaration.
Merge remote branch 'origin/bugfix/8056_event_performance'