* this code adds a cookie when a special get parameter is set
* the content of this get parameter is used as value for the cookie
* the cookie expires after 20 seconds
* the JS code checks every 500 milliseconds for the cookie
-> if the cookie is set the request returned and the download is started
This enforces proper types on POST and GET arguments where I considered it sensible. I didn't update some as I don't know what kind of values they would support 🙈
Fixes https://github.com/owncloud/core/issues/14196 for core
maintain deprecated \OC::$session when getting or setting the session via the server container or UserSession
restore order os OC::$session and OC::$CLI
remove unneded initialization of dummy session
write back session when $useCustomSession is true
log warning when deprecated app is used
It was not possible to download a file called "true" or "false" (caseinsensitive) when clicking the link "download" due to the result of json_decode().
Both cases are now implicitly checked.
Hotfix provided by Herbert Pophal
