Add year and quarter to CourseContract
Reorganize imports
Add year and quarter to DbHandler table creation
Add year and quarter to Course class
Protect fromCursor methods from partial cursors

Because of projections, a cursor might not contain all of the data
columns that we expect. So test for -1 before trying to get the data
from the cursor.
Add comment about selection of courses
Add quarter constants Course class
Specify a default year and quarter

When they are not specified in the selection. But only for a multi-value
query on courses.
Merge pull request #30 from RadicalZephyr/add-offered-time

Add offered time