Merge pull request #9 from mtiller/master

Fixing a few issues
Made a control component, started adding graphical annotations
Added graphical annotations for the components

SimSysTrial supposed to be for the graphical connections, but is not
working yet.
Graphic annotation of connectors

Need to make block connectors for the voltage, velocity, and such.
Graphical annotations - this fixes #10
addition to the connections

didn't properly save the last time, so redid them plus made different
graphical annotations
Fixed an issue with discrete systems of equations