Added support for Data Import Handler

Added ability for CFSolrLib to handle Data Import Handler (DIH) requests. Also, added ability to retrieve the information (via the THIS scope: username, password, isAccessAuthenticated, dataImportRequestHandler) one would need to hit the Solr server directly (say, via CFHTTP), if the programmer didn't want to go through CFSolrLib for DIH calls.
Merge remote-tracking branch 'upstream/master'
Merge pull request #10 from jamiejackson/data_import

Added support for Data Import Handler