Gracefully handle missing pytest-xdist distribution.
Hard failure instead of graceful, from feedback provided by vitaly
Merge remote-tracking branch 'upstream/master' into graceful-missing-pytest-xdist
Fixed bug in boosting calculations. Boosting was being turned off
when highTier was off.
Merge pull request #442 from oxtopus/graceful-missing-pytest-xdist

Detect missing pytest-xdist module
Reduced the amount of drift between implementations by reducing the precision with which we initialize permanences. There is still some drift in permanence values though.

Fixed serialization bug with FlatSpatialPooler. The swig bindings were using inherited pickle implementations from the parent class SpatialPooler.

Got previously failing tests to pass.
Merge branch 'master' of github.com:numenta/nupic into issue_340
Fixed getNumpyRandomGenerator to set lower resolution seed values
Issue 340

Fixed some typos

Put common SP creation code into algorithm_test_helpers.py

Responded to pull request feedback.
Merge pull request #453 from subutai/issue_340

Bug fixes for Issue 340
Merge branch 'master' into silence-warnings