* Python type tracking now follows values stored in instance attributes such as `self.attr` across instance methods, including across a class hierarchy (for example, a value stored on `self.attr` in a base class and read in a subclass, or vice versa). As a result, analysis is more likely to recognize user-defined objects that are stored on `self` and used later in other methods, which may produce additional results.

* Simplified the internal predicates that detect `@staticmethod`, `@classmethod` and `@property` decorators to match the decorator's AST `Name` directly, rather than going through the CFG and requiring the name to resolve globally. Code that shadows these three builtin decorators at the module-scope will now be classified by the decorator name alone; in practice, shadowing these names is extremely rare and the call-graph results are unchanged.

* Python taint tracking is now more precise for values flowing through container contents, such as list, set, tuple, and dictionary elements. This may remove some false positive alerts.

* When a guard such as `isSafe(x)` is defined, we now also automatically handle `isSafe(x) == true` and `isSafe(x) != false`.

- The modelling of Psycopg2 now supports the use of `psycopg2.pool` connection pools for handling database connections.

* The sensitive data library has been improved so that `snake_case` style variable names are recognized more reliably. This may result in more sensitive data being identified, and more results from queries that use the sensitive data library.

Hence it is no longer needed to provide `none()` implementations of these predicates if they are not needed.

* Deleted many deprecated predicates and classes with uppercase `API`, `HTTP`, `XSS`, `SQL`, etc. in their names. Use the PascalCased versions instead.

* Deleted the deprecated `getName()` predicate from the `Container` class, use `getAbsolutePath()` instead.

* Deleted many deprecated module names that started with a lowercase letter, use the versions that start with an uppercase letter instead.

* Deleted many deprecated files from the `semmle.python.security` package.

* Deleted the deprecated `BottleRoutePointToExtension` class from `Extensions.qll`.

* Type tracking is now aware of flow summaries. This leads to a richer API graph, and may lead to more results in some queries.

* Some unused predicates in `SsaDefinitions.qll`, `TObject.qll`, `protocols.qll`, and the `pointsto/` folder have been deprecated.

The old name still exists as a deprecated alias.

The old name still exists as a deprecated alias.

The previous files still exist as deprecated aliases.

The old name still exists as a deprecated alias.

The old name still exists as a deprecated alias.