[Jenkins 21880] weblogic-deployer-plugin support

This pull request adds support for the weblogic-deployer-plugin.

As this is my first Groovy project I would like to get some feedback on code quality and architecture. So please review my code. Especially I'm unsure whether the **task** sub section is implemented right. In the mean time, I'll add a last peace of code for the deployment trigger parameters.

I tested the plugin on Jenkins 1.532.1 and weblogic-deployer-plugin 2.9.1 running on Windows 7 deploying to WebLogic 12c.