Enhance wsssh and wsssht with improved functionality

wsssh improvements:
- Parse SSH arguments for -p option to extract port value
- Automatically add --wssshd-port to ProxyCommand when -p is specified and --wssshd-port is not explicitly set
- Fix build warnings in find_wsssht_path function
- Change debug mode to execute SSH command instead of just printing it

wsssht improvements:
- Modify pipe mode debug output to use stderr instead of stdout
- Prevent debug messages from interfering with piped data streams
- All debug output in pipe mode now goes to stderr to avoid contaminating stdin/stdout

These changes improve the usability and reliability of both wsssh and wsssht applications, especially when used in pipe mode or with SSH port specifications.