Fix compilation on Solaris
BUG: Fixed github stats retrieval

Currently urllib is used to retrieve a json file from Github, however
Github url used is not static url, urllib2 required to retrieve
information from Github.
Bug: alpha parameter was ignored when fill color is #000000
BUG: Fixed object type missmatch in SymLogNorm

Currently SymLogNorm accepts both linthresh and vmin, vmax with their
native dtype, meaning that the contents of one object cannot be updated
with another due to a mismatch of types.
Merge branch 'v1.3.x'

* v1.3.x:
  Document API change in hist
BUG: fixed shape validation for manual conf intervals in boxplots
TST: fixed new test and added baseline PNG
Install numpy as a setup_requires dependency so pip will install Numpy first
Fix installing numpy as a setup-time dependency
Add tests for installing into a completely clean virtual environment.
add option to delete empty PdfPages when closed

 - PdfPages objects can be told at initialization to delete the pdf file
   when closed, if no page was actually plotted
 - keep the default to not delete empty pdf files so current behavior is
   not changed
 - also some basic tests for it
Python 3 fixes
clearer comments in test
refactor docstrings of PdfPages
pep8 clean up (file seems to have been created with indentation of 3
spaces!)
a bit more pep8 work
Rename C++ variables to avoid use of reserved identifiers
Merge pull request #2445 from mdboom/numpy-setup-dependency

Declare Numpy as a setup dependency
Fix #2300: deal with the case where there are no writable directories.
Fix #2425: setters without arguments should not be added to the list of
parameters