Parser

- Now tags ORIGINAL arguments that were quoted or escaped with QUOTED.
Task

- Quotes arguments for readability.
Duration

- Now distinguishes between duration that require prefix quantities ('days') and
  those that do not ('annual').
Task

- Now recognizeѕ '', "" and <blank> as examples of an attribute values that
  should be cleared.
Unit Test

- Removed character (!) from task project name that was causing a _neg_ operator
  to be invoked.