Style Cleanup.

Delete Copy Constructors and Assignment Operators, or explicitly implement them.
	src/Compiler/AST/Class.h
	src/Compiler/AST/Context.h
	src/Compiler/AST/Expression.h
	src/Compiler/AST/Method.h
	src/Compiler/AST/Statement.h
	src/Compiler/AST/Type.h
	src/Compiler/AST/Variable.h
	src/Compiler/AST/Verifier.h
	src/Compiler/CodeGen/IPlatform.h
	src/Compiler/Diagnostics/FileRange.h
	src/Compiler/Diagnostics/IReporting.h
	src/Compiler/Diagnostics/StreamReporter.h
	src/Compiler/Language/MiniJava/Context.h
	src/Compiler/Language/MiniJava/ContextBuilder.h

Add a header with convenience macros.
	src/Compiler/Convenience.h