Fix size of delegate messages!

Blocking delegates were previously sending a bunch of extra info for
calculating latency around. Now just sending a single GA to the
FullEmpty for waking.
add bintsv4 input to graph500 graph represenation
Include Markdown docs in Doxygen, start work on Grappa title page.
fill in Grappa mainpage, try to speed up Doxygen, and ignore impl.
dumb -- Doxygen can't handle '.md' extension in link, doing it by hand
doxygen: drop 90's era header/footer and add search
integrate fine-grained shared message pool with prefetching