Insert select_region and interpret_region functions where appropriate in other reduction.py functions
Add default arguments to reduce_time_space_seasonal_regional
Refactor seasonal climatology functions -- try to push all special cases into one function.
A number of small syntax bug fixes and small code cleanups.
Make metadiags.py executable.
bug fixes -- variable names in reductions.py
Bug fix: reduce2latlon_seasonal expects region argument
Fix bugs in calls to calculate_seasonal_climatology (reductions.py)
Replace cut-and-paste code with select_level function
Refactor reduceRegion function (using select_region)

Conflicts:
	src/python/packages/amwg/derivations/masks.py
Move region functions into another file to access without circular import
Bug fixes in calculate_seasonal_climatology

Conflicts:
	src/python/computation/reductions.py
Retain units in select_region
Delete singleton axis in select_lev
Refactor some code with generic functions and add delete_singleton_axis to select_lev function.
Add region argument into plot set 3, including function reduce2lat_seasonal.

Conflicts:
	src/python/computation/reductions.py
Refactor some code with generic functions and add delete_singleton_axis to select_lev function.
Refactor seasonal climatology functions -- try to push all special cases into one function.
A number of small syntax bug fixes and small code cleanups.
Add region argument into plot set 4, including called functions

Add region functionality to reduction functions including
- reduce2levlat_seasonal
- reduce2lat_seasonal
- vertical interpolation functions in amwg1.py