Fixed bug causing nested file read over webdav to fail
Work on post_share hook for files_encryption
New method in OCP\Share{}:: getUsersSharingFile()
Development shapshot
Implementing sharing support
New file-specific methods in lib/public/share
Changes to how keyfiles are stored
Updated specfile
added some TODOs
- moved the enrcyption of the filekey ifg file gets shared from the post shared hook to
  Crypt::encKeyfileToMultipleUsers() because this can be reused if files get unshared
- switch from preUnshare hook to postUnshare hook because afterward we can simply get the
  updated list of users with access to the file and call Crypt::encKeyfileToMultipleUsers()
unshare all should work the same like unshare single users
go back to preUnshare hooks since sharing doesn't trigger post unshare hooks
take group shares into account if we retrieve the list a all recipients
use right location of the file is the source and not the target it is shared to
also find users with access to the file if a folder above the actual file was already shared
add option to keep duplicates in the list of users with access to a file, e.g. for the unshare operation we need to know if access was granted more than once, for example as group share and as individual share
add post_unshare hook, also add public link shares to the list of user with access to a file
add post_unshareALll hook, update recursively all keyfiles if a folder was shared/unshared
create keypair for ownCloud with empty passphrase, will be used for public link shares
remove debug output, fix typo in file names
remove todo, it is already solved
remove debug output
Fixed wrong array key reference
Moved dependencies out of Crypt methods (encKeyfileToMultipleUsers)(DI)
Fixed bug preventing sharing with users other than 'ownCloud'
Added comments
Moved functionality into filterShareReadyUsers()
Other changes