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
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
Merge branch 'master' into sharing_mail_notification_master

Conflicts:
	apps/files/index.php
Merge branch 'master' into sharing_mail_notification_master

Conflicts:
	lib/public/share.php
revert broken 3rdparty reference
some small js fixes
some small fixes
fix PHPDoc
use template for txt and html mails to send notification mails