Implement IcingaSysconfDir variable.

Refs #5224
Use a shell script for the mail-service-notification command.

Refs #5224
Merge branch 'feature/mail-notifications-5224' into next

Fixes #5224
Fix icinga-version.h in dist tarballs.

Fixes #5226
Add sysconf dir to the version info message.

Refs #5224
Make object, type and variable names case-sensitive.

Fixes #5228
Migration: Fix timeperiod object name stripping.

Fixes #5230
Fix some more RPM warnings.

Fixes #5231
Debian: doing cmake before clean to include icinga-version.h.

Fixes #5233
Fix command name with special chars not being migrated.

Fixes #5234
Make sure IDO reconnect attempts don't recurse.

Refs #5235
Remove unnecessary host config update.

Refs #5235
Improve IDO query performance.

Refs #5235
Implement workqueue statistics.

Refs #5235
Merge branch 'feature/fix-ido-queries-5235' into next

Fixes #5235
Renice child processes.

Fixes #5237
Add generic-user template.

Fixes #5236

Signed-off-by: Michael Friedrich <michael.friedrich@netways.de>
Fix deadlock when rescheduling checks.

Fixes #5092
Fix initial check schedule.

Fixes #5240
Documentation: Fix service dependency example.

Fixes #5243