Export SOLR Usage Statistics data to intermediate format

bin/dspace stats-util --export
SOLR export, change bad IP addresses
Solr usage event export to handle previous version data

DSpace pre-3.0 only tracked view/download usage events. When DSpace 3 introduced workflow/search tracking, these older usage events didn't get converted. This commit adds a query to find them too.
Merge pull request #740 from LongsightGroup/DS-2267-solr-export

DS-2267 SOLR usage statistics to export to common format