SOLR-4741: Deleting a collection should set DELETE_DATA_DIR to true (back ported from branch_4x)

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/branches/lucene_solr_4_3@1483663 13f79535-47bb-0310-9956-ffa450edef68
SOLR-4752: There are some minor bugs in the Collections API parameter validation (backported from branch_4x)

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/branches/lucene_solr_4_3@1483664 13f79535-47bb-0310-9956-ffa450edef68
SOLR-4563: RSS DIH-example not working (backported from branch_4x)

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/branches/lucene_solr_4_3@1483665 13f79535-47bb-0310-9956-ffa450edef68