Config file support added
Coordinator.java:
-attempts to read configuration values from either DEFAULT_CONFIG or the file specified by --config option
-values read from config file are overwritten if --serial or --port options are used
-added exitWithReason(), replaced all calls to System.exit()
-if port number unspecified SimpleHttpServer will try to automatically find a port (starting at DEFAULT_PORT and incrementing by one if the port is not available).
-if port is specified (in config file or by --port) then _only_ that port number is tried.

coordinator.conf:
-added default configuration file.
-only values stored are serial port name and web server port number

Log.java:
-added Log.t to print terminal failures (failures that will bring down the whole coordinator system)

SerialConnection.java:
-added some default ports for Linux
-cleaned up the error reports a bit.  If a serial connection can not be established it should be clear why

SimpleHttpServer.java:
-added portAvailable() to test whether a port number is available for binding
-modified constructor so that auto-incrementing the port number can be enabled, disabled