#62 prevent out of control rebuilds when scrolling up to the top
#62 speed up scroll window swaps
#60 update name to make more sense
Turn highlighting on be default for standard test data
#60 improved scrolling tests to account for new async nature fo features
#62 make vertical sizing async from scrolling thread

Reduce DOM operations by an order of magnitude

Now trigger scroll event at proper times, even when shim-scrolls and
rebuilds happen

Cache the column content for rows for better scroll performance

Refactor a lot of code for performance enhancements
#62 make sorting and filtering thread-safe
#62 forgot to size expander container for cached row heights
Fix searching (highlighting) on sub rows

Collapsed rows with matching sub rows will now display expanded for as
long as the search term is active.
Merge branch 'Scroll-Optimization'