v0.19

Changes:

- write startup errors to default logfile
- add check_os_updates
- check_files: fix skipping folder to early
- check_eventlog: fix using event id
- check_drivesize: add freespace-ignore-reserved option
- fix wrapped scripts not found
- fix check_drivesize using random volume for sub path
- fix check_drivesize using root folder when checking non-existing path
- fix perf-config when using REST API
- fix timeout handling (fixes #96)