Fixed initialization of runtime context in combiners.
Change how DataSourceFormat is handled internally
Add implicit generation of UDT[T]

This helps when implementing custom scala data input formats.
Change DataSinkFormat to also allow easy implemention of custom formats
Change scala version to 2.10.3
disable uploading 'stratosphere-dist' to dopa server
Maven and build changes
- use "build" profile of maven, to avoid any download progress information
- Reduce logging verbosity of javadoc-plugin
- instruct maven-eclipse-plugin to download sources (so that users can debug through our code without actively downloading the code)
- Remove warnings in eclipse from the new git-commit-id maven plugin
Add support for using arbitrary Pact Value classes in scala frontend