Remove unused dependencies
Current dependencies:
RJSONIO (>= 0.96-0),
plyr (>= 1.7.1),
data.table (>= 1.8.2),
MASS (>= 7.3-22),
classInt (>= 0.1-19),
ggplot2 (>= 0.9.3),
labeling (>= 0.1),
XML (>= 3.0)
Some of the dependencies could be removed. This might require removing functions that are not working any more.