Behaviour of init functions has been centralised in `collector/init.go`,
and can be called during exporter startup. This allows the exporter to
control the timing of collector initialisation, rather than relying on
the import & `init()` method.
This should reduce unexpected behaviour arising from the use of
`init()`, such as #551.
Signed-off-by: Ben Reedy <breed808@breed808.com>
Related to #659, this is a breaking change!
Fixes
```
windows_time_ntp_client_time_source_count non-histogram and non-summary metrics should not have "_count" suffix
```
for the time collector.
Signed-off-by: Mario Trangoni <mjtrangoni@gmail.com>
Windows Server 2016 or newer is required for the collector, as the
perflib counters were not exposed in previous versions.
Signed-off-by: Ben Reedy <breed808@breed808.com>
