More succinct handling of command line errors and BSP tidy up.

bsps:
	* zed_E64G4_512mb/zed_E64G4_512mb.xml: Human readable format!

src/e-server:
	* src/main.cpp (usage_summary): Created from initial part of usage.
	(usage): Deleted
	(usage_full): Created from all but initial part of usage.
	(initPlatform): Call usage_summary instead of usage.
	(main): Call usage_summary instead of usage, except in the case of
	-h/--help when we call usage_full. Deal with case of unrecognized
	arguments, which were previously silently ignored.