Fix Issue 389: When there is a multi-column primary key, H2 does not seem to always pick the right index

Add new collation command SET BINARY_COLLATION UNSIGNED, helps with people testing BINARY columns in MySQL mode.

MVStore - improvement to free space management - saves us from having to generate a large BitSet every time we need to allocate a chunk

When using local temporary tables and not dropping them manually before closing the session, and then killing the process could result in a database that couldn't be opened (except when using the recover tool).

H2 Console: the session timeout can now be configured using the system property "h2.consoleTimeout".

Experimental off-heap memory storage engine "nioMemFS:" and "nioMemLZF:", suggestion from Mark Addleman.

Issue 431: Improved compatibility with MySQL: support for "ENGINE=InnoDB charset=UTF8" when creating a table.

Issue 249: Improved compatiblity with MySQL in the MySQL mode: now the methods DatabaseMetaData methods stores*Case*Identifiers return the same as MySQL when using the MySQL mode.