Group some global vars in isql (relative to the SET command).

git-svn-id: svn+ssh://svn.code.sf.net/p/firebird/code/firebird/trunk@59529 65644016-39b1-43b1-bf79-96bc8fe82c15
1.- Prevent special chars from disabling isql. 2.- Do not take offsets from null pointers.

git-svn-id: svn+ssh://svn.code.sf.net/p/firebird/code/firebird/trunk@59530 65644016-39b1-43b1-bf79-96bc8fe82c15
Fixed the issue with UNION ALL vs WITH LOCK reported by Claudio privately.

git-svn-id: svn+ssh://svn.code.sf.net/p/firebird/code/firebird/trunk@59531 65644016-39b1-43b1-bf79-96bc8fe82c15