Bug fix + new features

• Example file examples/K_linked_regions_multilocus.cc added
• Streamlined KTfwd::fwdpp_internal::multilocus_rec_mut
• The sugar types KTfwd::singlepop, KTfwd::metapop, and KTfwd::multiloc were refactored to inerit from KTfwd::sugar::popbase.
• Fixed error in KTfwd::multiloc where gametes were initialized with the incorrect count
• KTfwd::gamete_data_sane_multiloc was added to fwdpp/debug.hpp
• Issue #41 fixed. This issue affected simulations using the multi-locus API, and all simulations using that API need to be rerun. Sorry.
• The experimental API to sample_diploid was made more flexible via a new header file, fwdpp/experimental/dispatch.hpp. * This addition allows better fine-tuning of "rules" classes
• The experimental API now takes rvalue refrence (&&) instead of const reference (const &) for rules classes. This allows the rules to be written and be more idiomatic, avoiding use of mutable variables.
• Add overload of KTfwd::haplotype_dependent_fitness::operator() for custom diploids