New DataModel and Parsing
Implemented parsing through 3 passes:
CourseList
ProgramList
StudentList
Changed Data Model
Program-Course-Task
Student-Program
Student-(Task,Mark)
Made Singleton for StudentReportParser
Implemented View functionality.
Added Entity interface.
Added getTreeModel() to model.
This is first working prototype.
Added comments.
Added loading/parsing xml errors processing.
Merge pull request #1 from splavs/dev

Dev