Backport fix for CORE-4020
Instantiate cpl applet methods with LPARAM instead of long.

git-svn-id: svn+ssh://svn.code.sf.net/p/firebird/code/firebird/branches/B2_1_Release@57593 65644016-39b1-43b1-bf79-96bc8fe82c15
Improve check for FBBUILD_FILENAME_SUFFIX env var

git-svn-id: svn+ssh://svn.code.sf.net/p/firebird/code/firebird/branches/B2_1_Release@57594 65644016-39b1-43b1-bf79-96bc8fe82c15