Implement display functions for GoogleIntegration

Implemented functions to test the Google Service and displaying of
calendar and tasks from the respective Google services.
Added StoredCredential to gitignore

The content of google_oauth_credential will be a StoredCredential file
after a successful OAuth is made by the person running this program.
This should not be replicated to every user, and should be unique for
everyone, for security reasons.
Merge branch 'master' of https://github.com/cs2103aug2014-w10-4j/main
Pass the test for modifyTask
Refactor a few methods
Update JUnitEventLogger.java
Add comments to LocalStorage
Merge local repo
Add DEFAULT_ constant variables

Constant variables for default calendar name as wall as default task
list.
Simple input parser for add, display and delete simple task
Merge branch 'master' of https://github.com/cs2103aug2014-w10-4j/main
Update to TasksController's Logic

TasksController has been updated to use a specific TaskList ID so that
it will not create or work on duplicated Task Lists.

In this update, the task ID has been hardcoded into the TasksController
class to ensure that things are working. Therefore, it is still
incomplete as it requires a further step to save the TaskList ID to the
host’s computer.

If the TasksController is unable to grab any valid TaskList from the
Google Account, it will simply create one and store the newly created
TaskList’s ID into the host. (to be implemented)
Merge branch 'master' of https://github.com/cs2103aug2014-w10-4j/main
Updates to TasksController Logic

Updated it to store (create new file if doesnt exist) the TaskList ID
to the host.

Updated it to retrieve the TaskList ID to the host.

Implementation not bulletproof, will work on strengthening the boundary
case when handling with these files on host.
Added TaskListId folder to Gitignore

The TaskList ID is specific to the user’s account and task list. It is
included in the ignore list so that the entries will not be corrupted
over commits.
Simple input parser for add, display, edit and delete simple task
Simple input parser for add, display, edit, done and delete simple task
Fixed a boundary case; Created TasksHandler

First, a boundary case related to getting the “ChirpTaskv0.1” TaskList
has been fixed. This problem arises when the ID of the previously
created TaskList has been corrupted or tampered with for example.

Second, a TasksHandler class has been created which is mainly used to
store static methods related to Google Tasks. Usage include checking if
a TaskList is null for now. (example: TasksHandler.isNull(TaskList)).
Implemented Add/Show Tasks/Lists for Google Tasks

This commit is entirely on Google Integration.

The add and show tasks methods have been implemented in the
TasksController as well as TasksHandler classes.

TasksHandler has been updated with more static methods to support the
Tasks operations.

TasksViewer has been updated with more static methods to support the
retrieval of task list (id/title/modification DateTime object)
Implemented Delete for Google Tasks

Delete function implemented to delete in a specific task in a specific
task list for Google Tasks using the corresponding Task ID and TaskList
ID.