SOLR-4503: Add REST API methods to get schema information: fields, dynamicFields, fieldTypes, and copyFields.  Restlet 2.1.1 is integrated and is used to service these requests.
Also fixes bugs in dynamic copyField logic described in SOLR-3798.
Also fixes a bug with proxied SolrCloud requests (SOLR-4210) when using the GET method.
(merged trunk r1453161)

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/branches/branch_4x@1453162 13f79535-47bb-0310-9956-ffa450edef68