Update setup.py to fix broken install on OSX
RLS: Get easy backport tool from IPython master.

RLS: Add attribution.
RLS: Update gh_api to curren IPython master.
RLS: Allow getting by milestone.
Merge pull request #1136 from jseabold/backport-tool

RLS: Add IPython tools for easier backporting of issues.
MAINT: Add stub for 0.6.0 release notes.
DOC: Update contributing notes.
DOC: Add docs on commit messages to contributing.
Merge pull request #1052 from jseabold/contrib-docs

DOC: Updating contributing docs
Merge pull request #1071 from benduffield/master

INSTALL: Update setup.py to fix broken install on OSX
BLD: Fix build issue on some versions of easy_install.
Merge pull request #1075 from jseabold/fix-matplotlib-sandbox

BLD: Fix build issue on some versions of easy_install.
BUG: Ensure 2d for conformability. Closes #1076.
TST: Test ARMAX prediction with 1d exog.
DOC: Clear up requirements for ARMAX prediction.
BUG: Make sure to distinguish 1d row vs 1d obs in predict
Merge pull request #1077 from jseabold/fix-armax-predict

BUG: Allow 1d exog in ARMAX forecasting.
ENH: exp(poisson.logpmf()) for poisson better behaved.