* Changed the `Issue` constructor to use an attribute map instead of an
increasingly long parameter list. Of course we lose some control over required
parameters.
* Added the Joda Time and SLF4J logging libraries.
* Implemented the `FileIssue` constructor for the new `Issue` refactor.
* `Issue` implementation is tentatively complete.
* Started ona direction for implementation with `FileIssue`.
* Revisiting the code for `XmlIssue` to polish it up. The XML code was never
really finished, but it should be for 3.0.x
* `FileRepository` was incorrectly returning the root project's first
set of subprojects for the `getRootProjects()` function, instead of the root
project itself.
* Implemented `walkProject` on `com.jdbernard.pit.Project`
* Updated several classes to fit the new interfaces/abstract classes.
* Still not finished with XML issue repository code.
libpit - Personal Issue Tracker core libraries (Filter, Issue, Project, Category)
pit-cli - Command Line Interface (CLI) to libpit
pit-swing - Graphical, Swing interface to libpit (built using Griffon)
libpit and pit-swing both build, though pit-swing is just an empty griffon poject.