SNClient

Changes:

 - relative include paths are now considered to be in the parent ini-file
 - wmi: improve error handling

Changes:

 - add configuration dialog to .msi installer
 - setup windows firewall rules during installation
 - add wildcard support for includes
 - add conf.d directory support for includes
 - added check_tasksched
 - added nrpe mode to test cmd
 - fix osx installer (#27)
 - fix linux check_drivesize (#14)
 - fix missing byte in nrpe response (#21)

Changes:

- implement external scripts
- add support for client certificates
- add hashed passwords
- improve internal checks