added new design choices, qs array impl

ASTDesign.lhs - added new choices loopiter (iteration) and looprec
(recursion)
ASTInternal.lhs - added new structures and modified to have enough
representation for qs using arrays
ASTJava.lhs ToJava.lhs PrintJava.lhs - added new structures and modified
to accommodate new design choices and array vs list implementations of
qs
ImplQuicksort.lhs ImplQuicksort.lhs - added DSL code for function
implementations (incl helper methods)
Report - text and code update plus added appendices