add HEX output, streamline program args

- add an option to dump as a hex file instead of binary
- change arguments to read with an optional --bin flag
- dump command is now suppressed from help menu
- implement erase suppress validation
- add ability to dump only non-blank pages
- add -h and --h but don't document
- combine flash commands with --eeprom and --user flags
- all old commands still fully supported (not documented)

TODO: update the manual pages