Catch more exceptions in DAV client

Added InvalidArgumentException to catch HTML parsing errors when XML was
expected.
Made convertSabreException more generic to be able to handle more
exception cases.

fix share input loading spinner, fix #15522

fixing #15396 & #15397

Properly catch guzzle 503 when querying share info

[command] delete orphaned file cache entries

Add password input from env variable for occ user:{add, resetpassword}

ajax/share.php should return correct list of suggestions

LDAP Wizard Overhaul

only create a db entry for the user in case of a name conflict on group share

change default value of ldap_tls to 0. It will be detected anyway, but starting with 0 will lead to errors and unconfigurability

Don't stop event execution for menu item click

Fix typos and some other adjustments

fixes #15326

* fixes #12326 - the settings menu is closed now, because the event is executed

Keep shares when deleting shared folders

Disallow Windows Server in Server Check

Will prevent users from use ownCloud on Windows Server 

Add an option to get the output in plain, json or print_r syntax

Hint for remote sharing syntax

Dont create exclude list for generating the share target

Check if the key exists, before trying to delete it

add link to installation documentation to setup page

Remove unneeded file