Look for OSX and Linux fonts in common places (#370 fixes)

[charleslaw]

Fix #370

[hugovk]

@charleslaw Please can you include test cases so this new code is covered?

https://coveralls.io/files/404711323#L242

Info on enabling Travis/Coveralls here: https://github.com/python-pillow/Pillow/blob/master/CONTRIBUTING.md

[charleslaw]

Added some tests. Also it's worth nothing I ran this on osx 10.9.5 (mavericks) and ubuntu 14.04.

[wiredfool]

Previously discussed in #682.

According to the freedesktop spec, XDG_DATA_DIRS should default to /usr/share. Adding that as a default would allow the linux case to work when XDG_DATA_DIRS is not set, such as a VM with no desktop installed.

[wiredfool]

Thanks for putting this together.

[SmoothJM]

why I still got the error:
Traceback (most recent call last): File "od_predict.py", line 34, in <module> object_detection(sys.argv[1]) File "od_predict.py", line 26, in object_detection r_image,box_count,left, top, right, bottom = yolov3.detect_image(image) File "/home/capstone/Capstone_web/server/public/keras-yolo3-master/yolo.py", line 133, in detect_image size=np.floor(3e-2 * image.size[1] + 0.5).astype('int32')) File "/usr/local/lib/python3.6/dist-packages/PIL/ImageFont.py", line 642, in truetype return freetype(font) File "/usr/local/lib/python3.6/dist-packages/PIL/ImageFont.py", line 639, in freetype return FreeTypeFont(font, size, index, encoding, layout_engine) File "/usr/local/lib/python3.6/dist-packages/PIL/ImageFont.py", line 188, in __init__ font, size, index, encoding, layout_engine=layout_engine OSError: cannot open resource