1. Never allocate empty statement - always use att->prepare() to create statement interface
2. Separated IStatement into 2 parts - statement itself and resultset.
3. Added stmt->openCursor() (and att->openCursor() for unprepared statements) to create IResultSet.
4. Always use IMessageMetadata (former IParametersMetadata) to pass message fromat info from client,
therefore avoiding need in BLR generation in client applications.
Also some cleanups, the most important are:
- meaningful ctor on Jrd::Lock, helping to avoid code dup
- avoid unneeded h-file dependencies, making boot build engine dependent
- Plugins API.
- Feature CORE-2700 - UDR (User Defined Routines) Engine - C++ API supporting functions, triggers and stored procedures.
- Feature CORE-2470 - Support for alternate format of strings literals.
- Feature CORE-2310 - DDL triggers.
- Feature CORE-2312 - PSQL Packages.
- Feature CORE-1209 - CONTINUE statement.
- Feature CORE-1180 - DDL syntax to change (not) nullable state of columns.
- Feature CORE-2090 - Support OVER () clause with current aggregate functions.
- Fixed CORE-2699 - Common table expression context could be used with parameters.
- Introduce ODS 12.0.
- Work in progress in type-safe parser.
- Refactor some DDL commands (procedures and triggers) from DYN to DdlNodes.
- Refactor virtual tables to use a class hierarchy instead of namespaces. This is basic thing, not based on the changes done in Vulcan. Window functions is based on this work.
- Refactor COMMENT ON and DROP FUNCTION from DYN to DdlNodes. COMMENT ON do not use GDML anymore, it uses DSQL with PreparedStatement class.
- Refactor EXECUTE BLOCK to StmtNodes.
- Refactor the IUDF to SysFunctions. That eliminates RDB$GET_CONTEXT and RDB$SET_CONTEXT from RDB$FUNCTIONS.
