If multiprocessing fails, don't use it during setup.
Merge pull request #2114 from mdboom/multiprocessing-during-setup-1-2

multiprocessing use should be optional during setup
Merge remote-tracking branch 'upstream/v1.2.x' into v1.3.x

Conflicts:
	setup.py
fix issue #1881, pgf: add style information for hatchings
pgf: add hatching to test figures
Merge pull request #2116 from pwuertz/fix_1881

fix issue #1881, pgf: add style information for hatchings
Fix some segfaults when using newer Microsoft fonts.
Use PyOS_snprintf
Properly encode the fontname when using in findfont
Merge pull request #2089 from mdboom/segfaults-ms-fonts

RuntimeError: Unknown C++ exception in several examples using PS or PDF backends on Windows
Merge remote-tracking branch 'upstream/v1.3.x'
Merge branch 'master' into topic/voronoi