Mailer removed from core

[olivergondza]

This commit removes mailer functionality from core and bundles in org.jenkins-ci.plugins:mailer in version 1.2.

Only files really modified are:
pom.xml
test/pom.xml
war/pom.xml

[slide]

The one problem I saw when I was originally looking at this is that the Mailer is what provides the Jenkins URL to other areas, even in the core. I didn't see changes to work around this in the files.

[olivergondza]

I understand that this is more of a nasty hack than a solution one can be proud of, but since it is a bundled plugin I dare to say it will work.

I guess several properties* (including jenkinsUrl) can be moved back to the core as suggested by Jesse Glick.

• https://groups.google.com/forum/#!msg/jenkinsci-dev/LF4z8gf0gzA/ZjirJvaz_tEJ

[kohsuke]

Thanks for doing this! This is an awesome awesome change.

To make this really work properly without breaking compatibility with earlier plugins, I added 5237146