Improve check-jobs-configuration jobs

Current behavior:

• print configuration errors
• send reporting email to atimic@nuxeo.com
• ignores multibranch and pipeline jobs
• discard ignores ["Folder":[],"AuxModel":[],"JobTemplate":[], "OrganizationFolder":[], "MavenModule":[], "MatrixConfiguration":[], "FreeStyleMultiBranchProject":[], "MavenMultiBranchProject":[]]

TODO:

• print errors with a prefix ERROR on execution
• the job must parse the output looking for errors
• send email from the job
• parametrize the scripts for dry-run/autofix (default is dry-run = report only)
• communicate to dev@nuxeo.com about the job, rules and doc
• documentation*
• send to devtools@nuxeo.com
• ask job owners to fix their jobs
• is it possible to send to owners + cc dev or devops ?

*Documentation:
cleanup https://doc.nuxeo.com/corg/isolated-testing/ ; move job config stuff to https://doc.nuxeo.com/corg/jenkins-job-configuration/
move https://doc.nuxeo.com/corg/jenkins-pipeline-usage/ from https://doc.nuxeo.com/corg/jenkins-plugins/ to https://doc.nuxeo.com/corg/jenkins-job-configuration/ (as a sub page)

• list rules
  • About "Discard Old Build", the properties set in the job are lost when setting properties in the Jenkinsfile: they must be ported; provide a sample of the related warning.

    [Pipeline] properties
    WARNING: The properties step will remove all JobPropertys currently configured in this job, either from the UI or from an earlier properties step.
    This includes configuration for discarding old builds, parameters, concurrent builds and build triggers.
    WARNING: Removing existing job property 'Discard Old Builds'
    WARNING: Removing existing job property 'Do not allow concurrent builds'
    WARNING: Removing existing job property 'GitHub project page'
    WARNING: Removing existing job property 'Rebuild Settings'
    WARNING: Removing existing job property 'This build is parameterized'
    WARNING: Removing existing job property 'Build triggers'

• provide a sample standard pipeline build with the requirements (=> update the one at root of jenkins-pipeline-usage)

TODO for the Scriptlers

• cleanup
• parameterize (see above)
• how to publish them?
• how to version them (they already are, since they are included in the Jenkins configuration but...)?

https://qa.nuxeo.org/jenkins/scriptler/showScript?id=enableTimestamper.groovy