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 `${VERSION}` and `${BUILD_DATE}` variables.

![bildschirmfoto 2013-05-27 um 16 45 40](https://f.cloud.github.com/assets/637549/568519/4826d1f6-c6dc-11e2-96f9-b5c3af50b559.png)
![bildschirmfoto 2013-05-27 um 16 45 45](https://f.cloud.github.com/assets/637549/568520/4a793886-c6dc-11e2-9722-7631ba546ee6.png)