Fixed assertion when restoring DB in non-existtent path with overwrite - reported privately by Dmitry

git-svn-id: svn+ssh://svn.code.sf.net/p/firebird/code/firebird/trunk@58200 65644016-39b1-43b1-bf79-96bc8fe82c15
Fixed CORE-4121: Segfault when engine is shutting down inside blob get/put function invoked from UDF

git-svn-id: svn+ssh://svn.code.sf.net/p/firebird/code/firebird/trunk@58201 65644016-39b1-43b1-bf79-96bc8fe82c15
Improvements and corrections to message builder and UDR.

git-svn-id: svn+ssh://svn.code.sf.net/p/firebird/code/firebird/trunk@58203 65644016-39b1-43b1-bf79-96bc8fe82c15
Made the ALTER SEQUENCE RESTART behavior standard compliant.

git-svn-id: svn+ssh://svn.code.sf.net/p/firebird/code/firebird/trunk@58204 65644016-39b1-43b1-bf79-96bc8fe82c15