Fixed some bugs and added some new graphics.

No bugs now. View, add and edit all work as they should. Also implemented a
add item menu button in view homework. Also created the expand item icon so
that users know to click the box in view. Still have yet to make only one
box open at a time.

Signed-off-by: Nicholas <nicholaslum444@hotmail.com>
Merge branch 'master' of https://github.com/nicholaslum444/NUSBuddy.git

Conflicts:
	src/com/nick/nusbuddy/AddHomework.java

Please refer to previous commit.

Signed-off-by: Nicholas <nicholaslum444@hotmail.com>