Use tuples with clauses, and only convert to lists if using an older version of pycosat
Start writing a heuristic for which algorithm to use
Correctly handle an empty equation in generate_constraints
Add a comment
Merge branch 'master' into lots-of-builds
Implement the swapping from minisatp

It doesn't really seem to make a difference, but I suppose it can't hurt.
Add the ability to use PB to find the minimal SAT solutions

Conflicts:
	conda/logic.py
min_sat can't handle iterables any more

Handle empty clauses to min_sat
Correctly chain clauses together
Make min_sat with alg!='iterate' do the right thing for unsatisfiable clauses
Fix min_sat
Correctly handle alternate min_sat algorithms in resolve
Allow to speed up bisection with evaluation
Use evaluate_func in min_sat
Allow to set the polarity for ITE and build_BDD

If only one polarity is used, then as many as half of the clauses may not be
needed.
Set the polarity for BDD in generate_constraints
Add polarity argument to And, Or, and Xor
Restore the ConnectionError handler

Fixes #755
Always fail with connection error in download

It can't do anything if the resp is not defined, and the connection error is
raised by get, not raise_for_status.
Fix conda update to correctly not install packages that are already up-to-date

It was checking the build string, not the build number, so it was thinking
that things like np18py26_0 was newer than np18py27_0.