Collective.cron

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- Add a fake request so code called that expects a request will still work [dmarks]
- Allow python scripts and other TTW code to be called from collective.cron [djay]

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- Fix various github bugs (typos, install setup, dependencies) [kiorky, gforcada, khink]

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- fix 1 & 2 [kiorky]

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- optimize API to get job status infos [kiorky]
- make better robust code [kiorky]

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- Add a log limit property to logs to limit memory & other resources usage [kiorky]
- Performance tweaks [kiorky]

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- better registry handling [kiorky]
- better jobrunner [kiorky]
- better tests [kiorky]
- make install and restart code more robust, again [kiorky]