- Fix config file loading on Unix if no config file is specified.

- Fix config file loading on Unix if no config file is specified.
  Since r1.97 Privoxy would always interpret the last argument as
  config file, even if it's a valid command line option.
- Abort in case of unrecognized command line options. Closes #1719696.
- Remove a bunch of unnecessary strcpy() calls (yay for c&p without thinking).
- Replace the remaining strcpy() and strcat() calls with strlcpy() and strcat().