Big assertion capture refactoring.

- moved as much logic out of the macros as possible
- moved most logic into new ResultBuilder class, which wraps ExpressionResultBuilder (may take it over next), subsumes ResultAction and also takes place of ExpressionDecomposer.

This introduces many SRP violations - but all in the name of minimising macro logic!

include/internal/catch_interfaces_capture.h

@@ -34,13 +34,11 @@ namespace Catch {
         virtual void pushScopedMessage( MessageInfo const& message ) = 0;
         virtual void popScopedMessage( MessageInfo const& message ) = 0;
 
-        virtual bool shouldDebugBreak() const = 0;
-
-        virtual ResultAction::Value acceptExpression( ExpressionResultBuilder const& assertionResult, AssertionInfo const& assertionInfo ) = 0;
-
         virtual std::string getCurrentTestName() const = 0;
         virtual const AssertionResult* getLastResult() const = 0;
     };
+
+    IResultCapture& getResultCapture();
 }
 
 #endif // TWOBLUECUBES_CATCH_INTERFACES_CAPTURE_H_INCLUDED