Modified isDeleted condition in GoogleController

Instead of hardcoding isDeleted = true, it now uses the feedback from
the respective delete methods.

True if deleted, False if it is not.
Added addTimedTask function to GoogleController

Made changes to TimedTask class: From getDate and setDate to
getStartDate and setStartDate.

Fixed some methods that threw IOException before UnknownHostException.

Added a method getEventDateTime in DateTimeHandler. This method will
generate a EventDateTime object for Google Calendar’s API.

Modified DateTimeHandler to use a fixed constant time zone defined in
the program rather than using the default from the host’s machine.