title: Solrcloud delete collection bug?
body: <p>First,I create a collection called <strong>usercollection</strong>:</p>
  
  <pre><code>http://xxxxx/solr/admin/collections?action=CREATE&amp;name=usercollection&amp;numShards=3&amp;replicationFactor=3&amp;maxShardsPerNode=3
  </code></pre>
  
  <p>Then I found something wrong, so I delete it.</p>
  
  <pre><code> http://xxxx/solr/admin/collections?action=DELETE&amp;name=usercollection
  </code></pre>
  
  <p>At last ,I want to create the collection again. And I found something wrong.</p>
  
  <pre><code>`May 16, 2013 8:32:23 PM org.apache.solr.cloud.OverseerCollectionProcessor run
   INFO: Overseer Collection Processor: Get the message id:/overseer/collection-queue-    work/qn-0000000000 message:{
  "operation":"createcollection",
  "numShards":"3",
  "maxShardsPerNode":"3",
  "createNodeSet":null,
  "name":"usercollection",
  "replicationFactor":"3"}
  May 16, 2013 8:32:23 PM org.apache.solr.common.SolrException log
  SEVERE: Collection createcollection of createcollection           failed:org.apache.solr.common.SolrException: collection already exists: usercollection
      at org.apache.solr.cloud.OverseerCollectionProcessor.createCollection(OverseerCollectionProcessor.java:311)
      at org.apache.solr.cloud.OverseerCollectionProcessor.processMessage(OverseerCollectionProcessor.java:160)
      at org.apache.solr.cloud.OverseerCollectionProcessor.run(OverseerCollectionProcessor.java:112)
      at java.lang.Thread.run(Thread.java:662)`
  </code></pre>
  
  <p>So, I think the collection API has something wrong when delete.Thus, how can I really delete a collection?</p>