ENH: Added helper to get all files.

To be merged into master immediately.
ENH:  More setup for iterating over lambda x pi hyperspace.
ENH:  Add in py_opt_loop
REF/API: Fixing truncated_normal problem

Updating load_params to follow new policy of truncated_draw
returning draws and not a frozen distribution.

Also renaming trunc, ln_dist, fine_grid, grid > w_grid
              shock > z_grid; fine_shock > z_grid_fine

Still need to go the the code and change downstream stuff.
BUG: fixup truncat_draw
REF/API/BUG  Continued renaming following grid > w_grid etc.
BUG/ENH:  Implements weighted average now that I'm using z_grid.

This one hurt my heads a bit, but the idea with the panel
is to get the weights using that shocks pdf.  Then with the weights,
multiply the unweighted values in each frame (this is the apply),
and then sum to get the weighted average.
ENH/BUG ƛxΠ hyperspace introduced and write Metadata.

Too much in this commit but oh wells.
BUG:  Finish renaming to zgrid and get zn from parameters.json
ignoring old results.  Need some vc on those!
BUG:  CHange get_rigid_output to respect new distribution modeling.

Still not 100% on this.

Also fixed a bug on the weighed average.  Used the wrong name.
going to conflict w/ other branch.
BUGS:  Get wage distribution to go from 1 to 1 and get zn in
params.

Bug 1 has to get into master.
helper to figure out wth is going on
CLN/PERF:  Reduce number of test gridpoints.

This tests the algorithm while still testing it.

Also cleans up imports and finshing grid > w_grid renaming.
Merge branch 'rethink_distribution'

Conflicts:
	.gitignore