added new relic
added checked items method to board
changed methods to use board checkitems method
added performance tests for checklists
added data point builder
changed class to return data for lists even they are not in board
added new implementation for checklist time series in attempt to improve performance
extracted time series builder to its own class
refactored builders for a cleaner code
Merge pull request #4 from magnetis/performance

Rafactored the checkitems time series builder to improve performance.