Update to 1.0.0 and simple Maven 'installJar' and classes for declarative complex task

Two commits:
1. Upgrades to 1.0.0 - you can bring it to a branch or to main as per https://github.com/loicrouchon/ceylon.build/issues/17
2. This brings back the original `installJar` task, without dependencies
3. Introduces classes ported to Ceylon from aether that will be used in the declarative task for complex install Jar with dependencies.  The complex task will do exactly what 'export jar' does from eclipse IDE