Rakefile: Use test task from hen.
lib/lingo/attendee/tokenizer.rb: Record token position.

Related to #14.
lib/lingo/attendee/text_reader.rb: Don't remove line endings.

Let the Tokenizer handle all whitespace.
lib/lingo/attendee/text_reader.rb: Refactored filter processing.
lib/lingo/attendee.rb: Make #control and #process accept additional arguments.

Dropped AgendaItem along the way and extracted command responsibility from #forward.
lib/lingo/attendee/tokenizer.rb: Record byte offset.

Related to #14.
Rakefile (test_ref): Include `lib` directory and skip missing files.
lib/lingo/attendee/vector_filter.rb: Print position and byte offset with each word.

Closes #14.