Added two boolean options for record filters.
Added functionality to allow users to implement functions to be used as predicates.
Added unit tests for predicates. Got predicates compiling, and passing on tests.
Removing predicate functions to prepare for pushing or/not filters. Limits number of features pushed.
Merging in changes from main repository that I have forked from to minimize work after pull request.
Merge pull request #179 from fnothaft/master

Added Or/Not logical filters for column predicates