SOLR-6829: Added getter/setter for lastException in DIH's ContextImpl

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/branches/lucene_solr_4_10@1643855 13f79535-47bb-0310-9956-ffa450edef68
LUCENE-6097: mark abort/waitForMerges deprecated

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/branches/lucene_solr_4_10@1643897 13f79535-47bb-0310-9956-ffa450edef68