Adding the possibility to provide a pattern for the .ipa file name

Further I extracted the marketing and technical version to its own section. Don't worry, the german localization hasn't been pushed. I'll translate the rest and do a separate pull request.

As suggested I used the EnvVars for the ${BASE_NAME}, ${VERSION}, ${SHORT_VERSION}  and ${BUILD_DATE} variables.

This extends this https://github.com/jenkinsci/xcode-plugin/pull/29 pull request.