Gradle

See #110

I've reordered a one or two things and attempted to bring a little more clarity

to this topic in the Java Library Plugin chapter of the user manual. I have

also linked directly to this particular section from the main Building Java

projects chapter so that it gets more attention.

* `ProjectLayout.filesFor()` -> `files()` (we already have `file()` and we are replacing `Project.files()`, moreover the `For` suffix doesn't seem to add anything)

* `ProjectLayout.mutableFilesFor()` -> `configurableFiles()` (the result is of type `ConfigurableFileCollection`, and we regularly use "configure" as a term in our public APIs, while we don't use "mutate")

Resolves #5035.

Using dynamic Groovy had a noticable effect on some scenarios.

Use CompileStatic instead to reduce noise in the profiling results.

Issue dotorg-docs#219. Added a note that users can use the Gradle import

feature of IDEA without applying the IDEA plugin.

I have also converted tables to definition lists and cleaned up the indentation

of code samples.

Use Lookup to invoke defineClass on Java 9+

Increase memory for performance test JVM

Add support for signing publications and publishing signature files to Maven/Ivy repositories

Fail the build if a referenced init script does not exist

Issue: #4920

Signed-off-by: Andrew Potter <apottere@gmail.com>

The feature is triggered by the "--update-locks org:foo,org:bar" command

line flag.

This filters out the constraints for dependencies to update and applies

the other constraints as "prefer" instead of "strict".

Fixes #4906