Throw an explicit error to make it clear we don't support the TRIGGER combination of SELECT and FOR EACH ROW.

Throw an explicit error to make it clear we don't support the TRIGGER combination of SELECT and FOR EACH ROW

Apply #418: MySQL compatibility: support for ALTER TABLE tbl_name MODIFY [COLUMN] col_name column_definition, patch from Ville Koskela.

suggestion from markaddleman@gmail.com

There was a possibility that the .lock.db file was not deleted when the database was closed, which could slow down opening the database.

Optimize IN(...) queries: there was a bug in version 1.3.170 if the type of the left hand side didn't match the type of the right hand side.

When using trace level 4 (SLF4J) in the server mode, a directory "trace.db" and an empty file was created on the client side. This is no longer made.

Patch by lukas.eder@gmail.com

Optimize IN(...) queries: there was a bug in version 1.3.170 for comparison of the type "X IN(NULL, NULL)". Fixed.