Windows service and other performance enhancements

1. Support for deploying as a Windows service - see OpenAS2HowTo.pdf for details
2. Allow all components in the config.xml to use the attribute enhancer feature.
3. Fix possibility of logs getting cleared
4. Fix the DB logging module not being able to use the "tcp_server_start" parameter is always true in previous versions.
5. Optimise the move file method
6. Optimise the HTTP client handler
7. Rationalise the PID environment variable name to match between service script and startup script