[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
Merge pull request #1737 from artem-sidorenko/patches_antivirus_cleanup

New storage ids and small fixes for files_antivirus