Fixed DB object id leak for local temp tables.

Checkstyle config fixed to work with the latest 6.5.0 Checkstyle

See https://github.com/checkstyle/checkstyle/issues/473

Java 8 compatibility for regexp_replace and tests

References to BLOB and CLOB objects now have a timeout. The configuration setting is LOB_TIMEOUT (default 5 minutes). This should avoid growing the database file if there are many queries that return BLOB or CLOB objects, and the database is not closed for a longer time.

MVStore: concurrent changes to the same row could result in the exception "The transaction log might be corrupt for key ...". This could only be reproduced with 3 or more threads.