Changed syntax of user definition operators according to discussion in devel
Added virtual table sec$user_attributes with parsed user's attributes
Implemented CORE-2004: Ability to alter user inactive/active
Implemented CORE-2063: Added CREATE OR ALTER USER operator
Implemented CORE-3931: Ability to set comment for the user


git-svn-id: svn+ssh://svn.code.sf.net/p/firebird/code/firebird/trunk@58945 65644016-39b1-43b1-bf79-96bc8fe82c15
Documented changes in SQL user management

git-svn-id: svn+ssh://svn.code.sf.net/p/firebird/code/firebird/trunk@58946 65644016-39b1-43b1-bf79-96bc8fe82c15
Misc

git-svn-id: svn+ssh://svn.code.sf.net/p/firebird/code/firebird/trunk@58947 65644016-39b1-43b1-bf79-96bc8fe82c15
Implemented CORE-3365: Extend syntax for ALTER CURRENT USER

git-svn-id: svn+ssh://svn.code.sf.net/p/firebird/code/firebird/trunk@58948 65644016-39b1-43b1-bf79-96bc8fe82c15