Revert auto-registration of function aliases (tests fail); fix for "Transaction log could not be truncated"

The message "Transaction log could not be truncated" was sometimes written to the .trace.db file even if there was no problem truncating the transaction log.

auto-registration of function aliases

H2 Console: HTML and XML documents can now be edited in an updatable result set. There is (limited) support for editing multi-line documents.

MVCC: concurrently updating a row could result in the row to appear deleted in the second connection, if there are multiple unique indexes (or a primary key and at least one unique index). Thanks a lot to Teruo for the patch!

Executing the statement CREATE INDEX IF ALREADY EXISTS if the index already exists no longer fails for a read only database.

Changed method visibility from package private to protected to allow indexes from external table engines use it.