Merge pull request #114 from danito/master

update fr translation
save moves dataset as an array instead of json

solves #113
if the dataset is saved as json, wordpress strips the trailing
backslash before the escaped unicode characters. saving it as a
serialized string works around that wordpress feature.
found here:
http://wordpress.stackexchange.com/questions/53336/wordpress-is-strippin
g-escape-backslashes-from-json-strings-in-post-meta
update fr translation and prepared hybridauth link for translation