DBD-Firebird version 1.18 is released

Firebird Perl driver version 1.18 is released with the following changes

• a bit more verbose ok() calls in 90-event-ithreads.t
• disable threaded event tests under AUTOMATED_TESTING
• Makefile.PL: check for ‘ibase.h’ presense in potential include dir
• allow empty (but still defined) DBI_PASS/ISC_PASSWORD for tests
• add support for FIREBIRD_DATABASE in tests’ environment
• adjust double tests to not fail with -Duselongdouble perl builds
• fix statement attr returns and rework 40-alltypes.t
• update installation notes wrt threaded perl and OpenSUSE
• add missing pointer initialization (RT#92821, Vadim Belov)
• dbd_st_finish: ignore “cursor already closed” error when closing the cursor
• dbd_st_execute: finish the statement if still active (RT#92810, HMBRAND)