Fixed mpi support.
Fixed a bug in smc related to the errorbar.
Added mpi example.
Made find_gamma() a little faster for the general case.
Added gamma_is_an_exponent flag in SMC.
Fixed two small bugs.
Started added ParticleApproximation.copy().
Added an all gather to the ParticleApproximation
A small change on hist().
Degenerate 1D arrays in ParticleApproximation become real 1D arrays.
Nothing special.