LUCENE-6082: remove abort() from codec apis

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1642558 13f79535-47bb-0310-9956-ffa450edef68
LUCENE-6082: simplify exception handling in simpletext .si format

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1642560 13f79535-47bb-0310-9956-ffa450edef68