Add auto configuration support for Spring Data Solr.

Registers required components in application context if not available to set up environment for usage with [Spring Data Solr](https://github.com/spring-projects/spring-data-solr). Will listen on `SolrServer` and `SolrRepositories` for configuration. 

By default an `HttpSolrServer` is registered unless a `zkHost` (zookeeper host) is defined. In that case an instance of `CloudSolrServer` will be created. 

By default `multicoreSupport` is enabled, creating instances of `SolrServer` for each core defined via `@SolrDocument`.

The current implementation uses `spring-data-solr-1.1.1.RELEASE`. The next version `1.2.0.RELEASE` is part of release train [Dijkstra](https://github.com/spring-projects/spring-data-commons/wiki/Release-Train-Dijkstra).

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Integration tests can be run against the default example configuration of Solr. 

1. Download und unpack Solr: http://www.apache.org/dyn/closer.cgi/lucene/solr/4.7.2
2. `$solr > cd example`
3. `$solr/example > java -jar start.jar`