Revert "FOCUS-5221: fix dataDir pathnames"

This reverts commit 4b728fca1c50d7cba2415ef1add00e6e65a4314f.
Revert "SolrJ changes required for FOCUS-4789. SOLR Jira SOLR-5922"

This reverts commit 8c12550fbd6f7c7e6dbdb04d9eab50631e2202c4.