Add Eclipse project files
Add Interface files for BakaTxt core functionality

Interface files:
- BakaTxtSession for a single user session
- Task to allow for instances of various tasks
- Database for interaction between the storage file and the user
Add skeleton file for BakaTxtSession
Add Implementations of Database and Task

Database allows other modules to perform CRUD on the stored Task. Basic
functionality is completed and tested. Undo has yet to be implemented.

Task contains all the methods that the user requires to manage a task, and for
the Database to process tasks from the storage file.
Add basic JUnit testing for Database and Task implementations