Modified ordered view frame to use cache.
faster check for grouping
modified nonnumericProcessLevel to look up items only if they get printed
proper handling of missing items
Replicated new ordered view frame design from text to numeric value types
Add "top-k" sorter to speed presenting short prefixes of all items.
Instead of sorting whole list to select top, extract top and then sort.
Exploited some more caching opportunities in order view frame.
factored duplicate code for order/possible order configuration
bugfix
Merge pull request #61 from karger/2013-10-30_orderedViewFrame_cache

2013 10 30 ordered view frame cache