Added a clear images button to the gui, and it works.
Made grid bag layout
Merge branch 'master' into gridbag

Conflicts:
	src/edu/lclark/drosophila/ButtonPanel.java
Put sample images in sample-images folder.
the x axis scales the data labels and the density of gridlines is constant
data labels on y-axis now scale correctly
Generalized the graph panel by changing the constructor.
merged master.
added graphPanel to analyzerPanel
Changed weights of graphPanel so it resizes correctly.