R2304

• added command line comment suport to ignore lines starting with a #
• added core file handling support, including direct http download
• added FTP binary transfer support
• enhanced sm command to print all event/action associations of states
• output of ls command could be better
• timer infrastructure must deal with invalid timer ids
• more event statistics
• added busy LED that shows activity of event and cyclic processing
• update stt command
• TCA9555 init fix
• fix: env output ignores printing format
• fix: timer argument parsing error