Flag SYS_FLAG_SHOW_LOGO added to EEPROM_SYS_FLAGS. The boot logo
functions check the flag and bypass the logo sequence if the flag
isn't set.
Added functions writeShowBootLogoFlag() and readShowBootLogoFlag()
for writing and reading the SYS_FLAG_SHOW_LOGO flag.
Renamed example sketch SetNameAndID to SetSystemEEPROM and added
the ability to set the SYS_FLAG_SHOW_LOGO flag, plus menus to reset
the system and user EEPROM areas.