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.

on ConcurrentHashMap, containsKey is faster than contains, since contains() is a synonym for containsValue, and will iterate over the whole map

Fix bug in MVStore when creating lots of temporary tables, where we could run out of transaction IDs.    

Concurrent CREATE TABLE... IF NOT EXISTS in the presence of MULTI_THREAD=TRUE could throw an exception.