Some edits regarding constants
Added search function and supporting methods/constants to Storage and
Task classes. UNTESTED
Writing unit tests.
Created another constructor for Task
Minor change in check for floating
Completed unit test for search - ran with no problems.
Modified withinDateRange to handle null dates.
Realised tester was clearing all tests due to bug (catch error and do
nothing). Removed tester and replaced with a main.java for testing.

Modified the search to accept multiple keywords and tags
Changed all Date instances to Calendar
Major changes:
Shifted all file reading methods in Storage to an internal class
FileHandler.
Modified the main tester and discovered a problem with the insertion
method: Tasks cumulatively added and file was not cleared
Fixed previous problem: File was not updated. Each operation read from
the old file. Fixed by removing all the reading and writing from it.
File is still not cleared at the end of tester.
Made add() method which uses the insert(). This way controller and
tester need not check which list to insert to
Put the readFile() and writeFile() back into insert() and delete().
Modified clearAll() function to write back to the file after clearing.
This way all tests can begin anew
Modified test cases. Discovered that floating file does not clear
correctly. In addition, TaskCount continues increasing even when files
are cleared
Found bug that was preventing floatingTask from being cleared:
determineFileName was using .equals() instead of ==. Fixed
Command-prompt display for now
Introduced recurring task. Modified taskCompleted from boolean to date.
Introduced al_task_recur
Turned taskDateTimes from ArrayList to LinkedList