MINDEXER-91: Add a Spring based example

- Corrected the README.md of the basic module as it was showing the wrong profile.
- Added a minimalistic Spring implementation with a simple service.
- Added two Spring contexts -- one for the actual maven-indexer specific classes and one for the the tests.
- Setup logging via SLF4J + Logback.
- Added README.md.
- Added a simple generator for valid artifact files (useful for testing without needing to have the resources under version control; this could probably be used in the indexer-core as well).
- Added a repository booter which creates test repositories with indexes.
17 files changed