Added feature

Added new feature which allows user to get information about when a
daysimeter was started. Log currently stores last 100 starts, easily
expandable.
Bug Fix

The program would hang when trying to access a calibration file not on
the LRC's server. This has now been fixed and tested by disconnecting a
machine from the network. The problem was due to trying to close a file
that had never been open and an if True statement.