Added Ui test cases for FeedbackPage

-> added more sessions in test data and changed html comparing files
accordingly
-> added html compare test for typical success case
-> added link tests that check all links
Added link test cases including target checks

Added functions that help to click the relevant link and return the New
Page as the return object.

The other page files now have a "isCorrectPage" function used to confirm
that the link worked.
Add tests to cover AccountsLogic
Do TODO, changed return type to void for some functions
Add assumption in getCourseInstitute
Add TODO in StudentsLogic - StudentAttribute should not be created  if course specified in it does not exist.
Move Account Level tests from LogicTest to AccountsLogic test.
Remove some unused imports.
Return if evaluation was already published
Add a test case for publishing an already published evaluation
completed action tests for FeedbackPageUiTest

-> revamped all the test cases be more effective and efficient
-> removed one test case
-> added helper functions in the InstructorFeedbacksPage.java
made the datepicker functions stateless
Merge branch 'master' of https://github.com/TEAMMATES/repo into Issue1900
standardised attribute names and refactored

-> created a method for recurring statements
more refatoring to create fillTime functions

allow pageUiTests to be able to edit the time values separately
slight change in behaviour of datePicker
started with DatePicker Test
Merge branch 'master' into Issue1918

Resolved Conflicts:
	src/test/java/teammates/test/cases/logic/AccountsLogicTest.java
Merge branch 'master' into Issue1908
completed ui test for datepicker

-> added helper functions in InstructorFeedbacksPage
-> added test cases in InstructorFeedbacksPageUiTest

NOTE: tests are volatile since they depend on focus/out-of-focus events.
Thus any change in the focus state of the browser will cause the test to
fail
Merge branch 'master' of https://github.com/TEAMMATES/repo into Issue1900
[1918] Clean up AccountsLogic

fixes #1918
Fixed unpublished action and added test cases

Allows unpublish action to return immediately with status message to
user if evaluation is no longer published.
Added some tests for this.
moved task queue related classes to logic.auotmated package