An ultimate solution for the CRT warnings targeted at both native and external (ICU, BTYACC) modules. Inspired by the ICU-only patch contributed by Dmitry Kovalenko.

git-svn-id: svn+ssh://svn.code.sf.net/p/firebird/code/firebird/trunk@57729 65644016-39b1-43b1-bf79-96bc8fe82c15