Move error statuses  to a separate class
Move scan statuses into DB
Add unit tests
Fix return value
[Antivirus] Some more checks when scanning uploaded files

Adapted original patch from Bart Visscher <bartv@thisnet.nl>
org. commit 46e4eccf57776ad9981e5551a4fb4a589a29034b in antivirus-cleanup branch
https://github.com/owncloud/apps/commit/46e4eccf57776ad9981e5551a4fb4a589a29034b
[Antivirus] Try with the OCP API to get the file to scan

Also remove old record before inserting the new one

Adapted original patch from Bart Visscher <bartv@thisnet.nl>
org. commit c29e49ab90290b8ae79a50817f96eea1cd208113 in antivirus-cleanup branch
https://github.com/owncloud/apps/commit/c29e49ab90290b8ae79a50817f96eea1cd208113
[Antivirus] fileid field is primary key

Adapted original patch from Bart Visscher <bartv@thisnet.nl>
org. commit 081b7c3cd3ddecc028e4f3f3025adfc7a436e9ba in antivirus-cleanup branch
https://github.com/owncloud/apps/commit/081b7c3cd3ddecc028e4f3f3025adfc7a436e9ba
Add support for the Home storage class

Adapted original patch from Bart Visscher <bartv@thisnet.nl>
org. commit 690d66037e40c1b37cbf01df367452b5905a65fc in antivirus-cleanup branch
https://github.com/owncloud/apps/commit/690d66037e40c1b37cbf01df367452b5905a65fc
$user is not known here, use fileid

Adapted original patch from Bart Visscher <bartv@thisnet.nl>
org. commit 4c9caa022a9caa2d050d7e862c1b1a0a2d5b2033 in antivirus-cleanup branch
https://github.com/owncloud/apps/commit/4c9caa022a9caa2d050d7e862c1b1a0a2d5b2033
Only scan files in the files dir

Adapted original patch from Bart Visscher <bartv@thisnet.nl>
org. commit 5334d8049d93cfbbf4ba5773b3888b513cbad50f in antivirus-cleanup branch
https://github.com/owncloud/apps/commit/5334d8049d93cfbbf4ba5773b3888b513cbad50f
namespaces fix
fixed required owncloud version and app version
remove old not existing background job by upgrade
fixed missing compatibility with PHP 5.3
Add admin configuration section
Fix indendation
Add backslashes