OwnCloud : ensure Notes folder exists (webdav)

try to make the directory in case it does not exist.
This commit implements this only for the webdav case.
ownCloud : create the Note directory (local)

In case ownCloud Client is used and not webdav,
create the Notes folder on local filesystem.
ownCloud : use create_file before replace_contents
fix a forgotten declaration
Prepare 3.14.2