Refactored names and signatures of methods and classes according to the
results of the last meeting.

Changes:
- Renamed InformationNeed to Information (the information need consists
of expected information AND parameters).
Merged ResolvedInformation and Information for reuse issues.
- Added concrete information, BooleanInformation and StringInformation
- Replaed Parameter (is a kind of information) and Service (no complex
information shall be resolved) with Information.
- Renamed JavaProvider to Java.