PopupDialogue.java
-Added null pointer check to controlEvent() method.

isualTimeline.java
-Encapsulated debug statements.
commit to pull
fixed merged conflicts
fixed some visualtimeline bugs and added a feature to click on a visual item in the timeline
slideShow.java
-Renamed Shuffle object from playToggle to playPause.
-Added key event callback method to handle controlling playback from the keyboard.
-Removed Shuffle.setState() method calls.

visualTimeline.java
-Updated selectedItemClicked() method header.

Quickshow.java
-Changed PApplet.main() invocation argument in main() method to properly enable Java application mode.
-Added variable to track currently selected VisualItem.
-Visual Item Properties button only appears if selected VisualItem is not null.
-Added some method headers.

PopupDialogue.java
-Removed unused Textarea references.
-Modified togglePopup() method to only display dialogue if passed a non-null VisualItem.

controlbuttonUI.java
-Removed unused prevSong and nextSong references.
-Visual Item Properties set to invisible by default.
-Removed unused Quickshow reference and constructor parameter.

FileBrowser.java
-Added loadFile() method header.

Removed visualTimeline.class.