Added FieldFilter class to act as a filter for story fields
Filtering happens during (not after) processing
Pivotal recieves no filter requests (all filtering done locally)
Support for "and" and "or" filters, filters for runs with iterations
Bugfix: Missing printline when running verbosely with iterations
Minor changes to README
Updated existing tests, added test file for FieldFilter
TODO: Test iterations, filters with PivotalHTMLParser
TODO: Test FieldFilter class
Added field/iteration tests for PivotalHTMLParser and tests for FieldFilter
Bugfixes to printlines and generated documents
Updated version and change log. New version: 0.3.0