Renaming configuration options, added graceful failures for http requests
coodinator.conf:
-renamed a number of options to better represent what they control
-split the file into sections for Main, Web server, Web frontend

Coordinator.java:
-renamed command line options to match config file
-removed --dummyserial option.  To use the dummy serial connection use "--serial dummy"

SimpleHttpServer.java:
-added private methods to generate generic 404 and 400 error pages
-added checks to IndexHandler and ResourceHandler so that 404 or 400 pages can be returned on errors

main.js:
-removed alert popup so the page can be tested easier