MINDEXER-91: Add a Spring based example

Added directory structures.
MINDEXER-91: Add a Spring based example

Extracted the currently existing examples into a separate module.
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.
MINDEXER-91: Add a Spring based example

- Committing forgotten change to parent pom.xml.
MINDEXER-91: Add a Spring based example

- Fixed the parent complaints.
MINDEXER-91: Add a Spring based example

- Fixed the pom's description.