Add icons

Change-Id: Ie55aa8624e138385da1d312926b2538c13dca658
Add more icons

Change-Id: I954abe9f54c0a777bbe76f20bd608954396fdd58
Refactor icons into single static instances

Icons are now constructed in one place and accessed through final static fields.

Change-Id: I1929d04f60d82b1d66d0aef50b1ce1a0eac2486f
Add input validation for tasks

If any required field doesn't have a valid value entered, a error message
shows up, the save button is disabled, and the field is highlighted with a
red border.

Change-Id: I9c378cb4118411dd7f57ce2273bfd96e7a6eb343
Merge branch 'feature/icon' into feature/gui2

Conflicts:
	TaskManager/src/main/java/edu/wpi/cs/wpisuitetng/modules/taskmanager/presenter/TaskPresenter.java
	TaskManager/src/main/java/edu/wpi/cs/wpisuitetng/modules/taskmanager/view/TaskView.java

Change-Id: I23db26435eba7f3e2080e7bc3bc7d6bf7ad13eab
Merge branch 'feature/gui2' into integration

Conflicts:
	TaskManager/src/main/java/edu/wpi/cs/wpisuitetng/modules/taskmanager/presenter/BucketPresenter.java
	TaskManager/src/main/java/edu/wpi/cs/wpisuitetng/modules/taskmanager/presenter/TaskPresenter.java
	TaskManager/src/main/java/edu/wpi/cs/wpisuitetng/modules/taskmanager/view/MiniTaskView.java

Change-Id: Ic410257070a36eaf555b71e7091922d3052b0332