Author: Andrew Nicols
MDL-52051 repository_dropbox: Add the V2 API
http://git.moodle.org/gw?p=moodle.git;a=commit;h=7609261d84fcf3858b67002da63ca0e2b6097284
http://github.com/moodle/moodle/commit/7609261d84fcf3858b67002da63ca0e2b6097284
+ 3.1 en [usev2api,repository_dropbox]
+ 3.1 en [uselegacyapi,repository_dropbox]
+ 3.1 en [legacyapihelpsupported,repository_dropbox]
+ 3.1 en [oauth2redirecturi,repository_dropbox]
+ 3.1 en [oauth2title,repository_dropbox]