Unbundle python-six (#1336740).

- Run tests (and temporarily disable failing ones).
- Use upstream-recommended way of running tests in parallel.
- python2-cycler and -mock are required for running tests.

20_matplotlibrc_path_search_fix.patch

@@ -22,3 +22,15 @@
      fname = os.path.join(path, 'matplotlibrc')
      if not os.path.exists(fname):
          warnings.warn('Could not find matplotlibrc; using defaults')
+--- a/lib/matplotlib/cbook.py	2016-05-20 14:14:52.000000000 +0200
++++ b/lib/matplotlib/cbook.py	2016-05-20 19:28:57.373601582 +0200
+@@ -823,8 +823,7 @@ def get_sample_data(fname, asfileobj=Tru
+     if matplotlib.rcParams['examples.directory']:
+         root = matplotlib.rcParams['examples.directory']
+     else:
+-        root = os.path.join(os.path.dirname(__file__),
+-                            "mpl-data", "sample_data")
++        root = os.path.join(matplotlib._get_data_path(), 'sample_data')
+     path = os.path.join(root, fname)
+ 
+     if asfileobj: