CodeSnip Old Code (SVN)

* Added new UTestHelpers unit to unit tests project to provide commonly used code for use by test cases. Only content is TAlwaysFreeController class. (Neglected to add UTestHelpers to SVN repo - see r980 for rectification).
* Modified various test case units that provided their own implementations of TAlwaysFreeController to use version in UTestHelpers unit.

* Added new DB.UCategoryGroup unit that provides a skeleton implementation of a category group in the database along with supporting types.
* Added test suite for DB.UCategoryGroup unit.

Added new DB.UBaseGroup unit containing abstract base class of all database classes the encapsulate a "group".

* Added new DB.USnippet unit that provides a skeleton implementation of a snippet along with supporting types.
* Added new DB.UConsts unit to provide basic type and constant definitions required by database code.
* Added test suite for DB.USnippet unit.

Removed unused field, method and constructor parameter from TestTObjectDestructionMgr.TTestDataItem.

Replaced private object destruction controller of TDBDataPool<T> with an instance of TObjectDestructionManager to permit or deny freeing of data items in the pool.

* Added optional Lock parameter to TObjectDestructionMgr.HookController method and added test to test case unit to check case when Lock is True.
* Changed anonymous function in TObjectDestructionMgr.Create to raise EBug if unknown permission kind detected.

* Added new Lock method, Locked property and new write accessor for FreeController property of TControlledConditionalFreeObject. Attempting to write a non-nil FreeController property when locked now raises new ELocked exception.
* Added ELocked exception to UBaseObjects unit.
* Added new unit test for Lock method and Locked property of TControlledConditionalFreeObject.

* Modified existing tests to compile and pass now that Controller property removed from TObjectDestructionMgr.
* Added new tests for new TObjectDestructionMgr.HookController method and for TObjectDestructionMgr constructor.

Replaced TObjectDestructionMgr.Controller property with HookController method.