Allows the user to specify either "12" or "24" to set whether or not to
display times in AM/PM format or 24-hour format.
Example:
gcal:
enabled: true
timeFormat: "12"
refreshInterval: 360
Fixes#665
Issue #600 points out Jenkins module panics occasionally
I noticed that a number of places panic because of JSON parsing
Centralize JSON parsing, have it return an error, and have widgets
report the error
