DUnit: Xtreme Unit Testing for Delphi SVN

Reorganized the choice of memory allocation function to support Delphi 2009

Remove the WideString overloaded flavor of CheckEquals and CheckNotEquals in Unicode compilation.
This overload causes compilation errors in many real world tests ("ambiguous call"), because it's very common to mix AnsiString with other string types.
This is already disabled in CLR out of necessity (where WideString = string).
Tests that require a WideString specific comparison can use the existing CheckEqualsWideString function.

Fix implicit string cast warnings in Tiburon.

Use floating string instead of AnsiString for calls to JCLDebug functions.

Synchronize TestFramework.pas with changes in the version in Tiburon version.
Adds new overloads for CheckEquals, CheckNotEquals for Int64 and Cardinal.
Also a #pragma for C++ support.

Remove AnsiString cast from LoadModuleTests which isn't required. This makes the LoadLibrary call compatible with Unicode compiler.

CaptureStackTrace is now a function.
When LocationInfo is nil, it's now displayed as 'n/a' rather than '$'

Platform warning off

System.IO added to the uses clause, so ExpandFileName can be inlined

Stack trace capture in Delphi.Net (contributed by Ralf Grenzing)