Fix #5519: Patch now support the 'None' linestyle

[Rezangyal]

If patch.linestyle is 'none', 'None', ' ', '' or None then no edge rendered (as in Line2D).
This fix #5519.

[tacaswell]

Please do not include None in this check. We reserve None to mean 'do the default thing' not 'do nothing'.

[tacaswell]

Can you also add a test (see http://matplotlib.org/devel/testing.html#writing-an-image-comparison-test + look at other tests in the test suite for how to do this)?

[Rezangyal]

ok, tomorrow.

[tacaswell]

@Rezangyal Can you please re-open this against the v2.x branch? There was a mistake on our side that needed to be fixed which required deleting the v2.0.x branch.

[Rezangyal]

I create a new branch (https://github.com/Rezangyal/matplotlib/tree/fix_linestyle_none),
but the test is not working to me.
When I set local_freetype = True in setup.cfg I receive an error message:

running build_ext
Building freetype-2.6.1.tar.gz
'"CFLAGS=\"' is not recognized as an internal or external command, operable program or batch file.
Traceback (most recent call last):
  File "setup.py", line 290, in <module>
    **extra_args
...
  File "setup.py", line 144, in run
    package.do_custom_build()
  File "x:\git\matplotlib\setupext.py", line 1000, in do_custom_build
    '--with-png=no --with-harfbuzz=no'], shell=True, cwd=src_path)
  File "x:\Python27\lib\subprocess.py", line 511, in check_call
    raise CalledProcessError(retcode, cmd)
subprocess.CalledProcessError: Command '['CFLAGS=" -fPIC" ./configure --with-zlib=no --with-bzip2=no --with-png=no --with-harfbuzz=no']' returned non-zero exit status 1

(python27 32bit, windows8.1)
maybe the 'set' is missing from command line

[mdboom]

When I set local_freetype = True in setup.cfg I receive an error message:

Sorry, I think that feature isn't yet working on Windows. @JanSchulz: can you confirm that, or should that be working?

[jankatins]

I haven't tried the internal freetype yet. There is a todo in #5629