#SB-137: Implement artifact searches via REST with XML/JSON results
- Polished up the code a bit.
- Removed commented out code.
- Made the search produce proper results that work with multiple repositories and storages.
- Refactored the ArtifactClient a bit.

#SB-57: Implement basic artifact searching classes
Implemented:
- SearchRequest
- SearchResults
- ArtifactSearchService
- ArtifactSearchServiceImpl

General:
- Fixed some storage/repository issues which were otherwise going to further develop into bugs.
- Added a baseUrl to the strongbox.xml so that it coule be used for search results (among other things).