1. Fix wrong timeout setting in join command, also alter the default timeout value to 10 seconds
2. Don't clear the CONNECTED_BIT when connected to AP.
1. Add command for Ethernet based on console component.
2. Make cmd_system and iperf a component that can be referenced by other examples
3. Add "version" command to cmd_system.c
4. Clean up the README.md in all ethernet examples[TW#26525]
