Add options and diagnosis tools when defining primary production

* Pass parameter to build_E_bar() to _not_ prefer the diagonal elements
  as primary products (and istead always pick the largest production,
  regardless of position)

* Check to quickly know how many:
	+ off diagonal primary products we have
	+ exclusive secondary products
	+ primary products with smaller production volume than one of
          their associated secondary productions.

 On branch smarter_Ebar
 Changes to be committed:
	modified:   pysut/pysut.py
Speed up code, leveraging numpy

* Use array multiplication rather than matrix*diagonalized_vector

* Use 1/vector rather than inv(diag(vector))

* Use internal array summation routines rather than summation vectors

 On branch smarter_Ebar
 Changes to be committed:
	modified:   pysut/pysut.py
improve documentation and unittest build_Ebar
Merge branch 'smarter_Ebar'
major speed improvements for alternate activity construct

* using scipy.sparse for many sparse matrix treatments, notably:
	+ in region_aggregation
	+ in defining Gamma
	+ in alternate technology matrix elaboration

 Changes to be committed:
	modified:   pysut/pysut.py
	modified:   setup.py
In definition of Gamma, option to exclude minority primary prods

 On branch speed_encapsulation
 Your branch is up-to-date with 'kbare/speed_encapsulation'.

 Changes to be committed:
	modified:   pysut/pysut.py