improved error messaging, initial commit
enable user to inform recipients about a shared file by mail
return mailSend status in getItems()
some clean-up
set sendMail status back to false
don't send mail to the user who shared the file
add expiration date if it is already set
encryption error messages, distinguish between a re-enabled encryption app and a password change from outside
improved documentation of the methods
error.php no longer needed
Merge branch 'master' into encryption_improved_error_messages_4617
Merge branch 'master' into sharing_mail_notification_master

Conflicts:
	lib/util.php
fix db queries
fix db queries
revert submodule reference changes
use css class hidden to hide setting elements
coding-style fixes
Merge branch 'master' into sharing_mail_notification_master

increased version number to trigger db update

Conflicts:
	lib/util.php
re-added error.php
no longer enforce log out, but provide useful errors/warnings instead