* Unify CPU collector conventions
Add a common CPU metric description.
* All collectors use the same `nodeCpuSecondsDesc`.
* All collectors drop the `cpu` prefix for `cpu` label values.
* Fix subsystem string in cpu_freebsd.
* Fix Linux CPU freq label names.
* Move NodeCollector into package collector
* Refactor collector enabling
* Update README with new collector enabled flags
* Fix out-of-date inline flag reference syntax
* Use new flags in end-to-end tests
* Add flag to disable all default collectors
* Track if a flag has been set explicitly
* Add --collectors.disable-defaults to README
* Revert disable-defaults flag
* Shorten flags
* Fixup timex collector registration
* Fix end-to-end tests
* Change procfs and sysfs path flags
* Fix review comments
Named return variables should only be used to describe the returned type
further, e.g. `err error` doesn't add any new information and is just
stutter.
This removes the requirement to run `node_exporter` as root or with read
access to `/dev/kmem` in order to get CPU usage statistics.
Once FreeBSD adds a macro for the `kern.cp_times` sysctl, the
`setupSysctlMIBs()` function should be replaced by usage of the macro.
Ben Kochie
Calle Pettersson
Karsten Weiss
Tobias Schmidt
Dominik Honnef
Johannes 'fish' Ziemke
Kai Storbeck
Kai Storbeck
Christian Schwarz
Brian Brazil
Kirk Russell
Matthias Rampke
Siavash Safi