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
Refactor WebAgg so it's easier to embed in other applications and run
over a server other than tornado.
Make figure larger.  Print address to console.
Let the Javascript side control when to fetch new frames.  draw_idle
sends a "draw" message to the browser.  If the browser is not already
waiting on another frame, it sends a "draw" message back to the server
which then returns an actual frame.  The nice thing about this approach
is that it's completely timerless.
Merge pull request #2420 from mdboom/webagg-factor

Refactor WebAgg so it can communicate over another web server
Merge pull request #2415 from kshramt/kshramt/fix_fill_opacity

Bug: alpha parameter was ignored when fill color is #000000
Catch stderr as well as stdout
Merge pull request #2441 from torcolvin/master

Catch stderr as well as stdout
Merge pull request #2406 from cpelley/fixed_stats-retrieve

BUG: Fixed github stats retrieval
make pep8 test routine reusable for other projects

Nothing changes for matplotlib test case but the routine can now be
imported and used from another project.
Also makes it better readable I think to have all the custom exclusions grouped
at the head of the file.
I also had to move the currently active manual skip to the bottom.
correct current skipping of pep8 tests for nose test discovery
Merge pull request #2486 from megies/reusable_pep8_testroutine

Make pep8 test routine reusable for other projects (work in progress).
Update scatter_demo.py

colors added
Merge pull request #2494 from ugurthemaster/master

Update scatter_demo.py
implement additional spectrum functions in mlab
implement improved mlab spectrum function tests and tests for additional mlab functions
implement additional spectrum plots in axes/_axes
Merge branch 'spec_stuff' of https://github.com/toddrjen/matplotlib into spec_stuff