#1 Allow DB to set internal course time format: long vs. BitSet

[Keith Lea]

A deployer of University Scheduler should be able to
easily describe that the course time data can be
represented internally as a 64-bit integer (a long), or
as a BitSet with a specified time block length. This
would help performance in some cases.

Some schools only offer courses on the half-hour; these
could be represented using a long. Others offer courses
at 5-minute intervals, so these must be represented
with a large BitSet.