fixed tests in order to reflect the new random suffix when overwriting files, fixed #239
fix with previous commit, #239
fixed typo with DEFAULT_PERMISSIONS, #234
fixed upload permissions, fixed #234
Merge branch 'stable/3.5.x'
unify json response with _upload_file (no matter if file already exists or not), #225
show resulting filename (e.g. with suffix, converted) after successful upload, fixed #225
fix with cycle tag for django 1.7
docs update for 3.5.7
translations update
docs updates