OAK-1702: Create a benchmark for Full text search

Perform 100 full text queries per test iteration to get more accurate test results.
Call getString() on the matching title/text properties and aggregate the results to prevent the JIT compiler from optimizing away unused bits of code.
Also give more time for initial indexing

git-svn-id: https://svn.apache.org/repos/asf/jackrabbit/oak/trunk@1587712 13f79535-47bb-0310-9956-ffa450edef68