Minor changes to how make_mocks calls the simulation object
Modifying make_mocks to support quenching features
Noticed strange bookkeeping bug in halo_type. Still unfixed. See note below.

Using the check_mock.py script, I created a Polynomial_Assembly_Biased_HOD_Model mock.
The default halo_type fraction has been set to 0.4 at all masses, and I find the following behavior:

In [13]: mock.halos['HALO_TYPE_CENTRALS'].mean()
Out[13]: 0.39999935006483106

In [12]: mock.halos['HALO_TYPE_CENTRALS'][mock.hasCentral].mean()
Out[12]: 0.67459118378954852

What's going on here? In what way does conditioning the halos on hasCentral
influence their halo type?
Identified cause of bug in make_mocks. See note.

Need to include an additional condition on maximum central destruction:
mean central galaxy abundance cannot exceed unity. Otherwise, in regions of HOD parameter space
where the destruction function results in values where <Ncen> exceeds unity,
there will be too few total centrals at that mass, since boosting <Ncen> above unity
can have no influence in the occupation statistics.
Still implementing the bug fix to assembly biased HODs. See note below.

I had not realized that there is actually a
non-zero minimum value of the destruction function
for centrals until today. This is not done being implemented, but is close.
Modified read_nbody to work properly on other machines.

Also included a couple of automodapi calls to mock_observables.
Deleted obsolete I/O routines
Modified read_nbody so that test_make_mock can be run using awkward workaround of py.test directory structure
Small changes to halo_occupation. Almost finished implementing minimum destruction.