Comment 0 for bug 1769013

There's a new ca-certificates-java package in debian unstable versioned 20180413 which conflicts with cosmic's version 20170930ubuntu1 [1] and requires a merge.

The following changes should be kept:
1) debian/control: Bump javahelper build dependency.
2) debian/rules:
2a) Explicitly depend on openjdk-11-jre-headless, needed to configure.
2b) Replace javac arguments '-source 1.7 -target 1.7' with '--release 7'
    as, per JEP-247, it also takes care of setting the right -bootclasspath
    argument.

And a new change should be considered:
- remove the creation of a default jvm-*.cfg file from debian/jks-keystore.hook.in as openjdk packages already provides a default jvm with the right configuration.

[1] https://merges.ubuntu.com/main.html?query=ca-certificates-java