Added db4o persistence (although not retrieval).
Introduce calculation of job and worker dissatisfaction (how far away they were from getting their first preferences).
Refactored JobSim.sensitivityMarketSim into MarketSimulation

# Please enter the commit message for your changes. Lines starting
# with '#' will be ignored, and an empty message aborts the commit.
# On branch master
# Changes to be committed:
#   (use "git reset HEAD <file>..." to unstage)
#
#	modified:   .cache
#	modified:   .classpath
#	modified:   src/JobMarket/Histogram.scala
#	modified:   src/JobMarket/JobSim.scala
#
# Untracked files:
#   (use "git add <file>..." to include in what will be committed)
#
#	lib/
#	simResults.db4o
#	src/JobMarket/MarketSimulation.scala