See if we can consolidate the left_mask/right_mask stuff.  Currently,
it's split across PathStrategy and Probability, not to mention in
profile.cc.

See if Haplotype can be implemented as a basic_string<Marker>
(problems with reference counting).

Create namespace FineMap;

Remove all the indirection to calculate probabilities.

Remove code that allows latents to be roots of trees.

Where else can we do major optimizations??

Audit to see where pointers should be owned or not in various classes.
Strong pointer (auto_ptr) usage recommended.

profile is HUGE!  Split up main()!

Documentation.

Idea: utility to generate latents given a file of observed haplotypes and
a disease location?  Then, make a complete graph of all nodes, and consider
each observed node as the root.
