Fixed monitoring_costs documentation in sgd.__init__.
Monitor.setup now checks for type of extra_costs.
changed monitor.setup check on extra_costs from OrderedDict to dict
updated test in test_monitor to use dict rather than OrderedDict
monitor.setup checks for OrderDict or dict for extra_costs. changed test to use assert_raises
test for extra cost runs through entire Monitor.setup method
Merge pull request #1067 from JesseLivezey/monitoring_costs

Fixed monitoring_costs documentation in sgd.__init__.