(libT) #5249 'error parsing json in some locales': add unit tests to test for this bug.

git-svn-id: svn://svn.transmissionbt.com/Transmission/trunk@13860 f4695dd4-2c0a-0410-b89c-da849a56a58e
(libT) #5249 'error parsing json in some locales': fix the bug; the new locale unit tests in json-test pass now

git-svn-id: svn://svn.transmissionbt.com/Transmission/trunk@13861 f4695dd4-2c0a-0410-b89c-da849a56a58e
bump NEWS

git-svn-id: svn://svn.transmissionbt.com/Transmission/trunk@13862 f4695dd4-2c0a-0410-b89c-da849a56a58e