Change image pygmae to use file handles instead of path because of unicode issues.
Change texture cache key to keep str type of the filename so we don't get encoding issues in automatic encoding.
Merge branch 'master' of https://github.com/kivy/kivy into image-unicode
Don't save open file.
Ensure filename is not auto converted bytes/unicode anywhere.
Fix unicode issues where python internally converts unicode to bytes.
Merge pull request #2170 from matham/image-unicode

Fix image unicode issues