Fix various issues.

git-svn-id: http://svn.code.sf.net/p/openmediavault/code/trunk@1520 3c3d7b80-5828-415e-9f61-280b98178fff
Refactor filesystem backend. Introduce class OMVFilesystemBackendAbstract. All supported filesystems must extend this class. Backends must be registered via OMVFilesystems::registerBackend.

git-svn-id: http://svn.code.sf.net/p/openmediavault/code/trunk@1521 3c3d7b80-5828-415e-9f61-280b98178fff
Enhance OMVStorageDeviceBackendAbstract class.

git-svn-id: http://svn.code.sf.net/p/openmediavault/code/trunk@1522 3c3d7b80-5828-415e-9f61-280b98178fff
Mantis 0001161: Send cron email about samba-recycle.

git-svn-id: http://svn.code.sf.net/p/openmediavault/code/trunk@1523 3c3d7b80-5828-415e-9f61-280b98178fff
Mantis 0001159: Allow to disable FTP login message. To disable the welcome message set OMV_PROFTPD_SHOW_DISPLAYLOGIN="no" in the file /etc/default/openmediavault.

git-svn-id: http://svn.code.sf.net/p/openmediavault/code/trunk@1524 3c3d7b80-5828-415e-9f61-280b98178fff
Improve code.

git-svn-id: http://svn.code.sf.net/p/openmediavault/code/trunk@1525 3c3d7b80-5828-415e-9f61-280b98178fff
Refactor filesystem backend.

git-svn-id: http://svn.code.sf.net/p/openmediavault/code/trunk@1526 3c3d7b80-5828-415e-9f61-280b98178fff
Improve cron scripts

git-svn-id: http://svn.code.sf.net/p/openmediavault/code/trunk@1527 3c3d7b80-5828-415e-9f61-280b98178fff
Mantis 0001162: Disk overview from raid creation screen has empty column serial number and vendor ATA.

git-svn-id: http://svn.code.sf.net/p/openmediavault/code/trunk@1528 3c3d7b80-5828-415e-9f61-280b98178fff
Mantis 0001162: Disk overview from raid creation screen has empty column serial number and vendor ATA.

git-svn-id: http://svn.code.sf.net/p/openmediavault/code/trunk@1529 3c3d7b80-5828-415e-9f61-280b98178fff
Mantis 0001157: System/Update Manager/ upload button. Increase nginx client_max_body_size to 25M.

git-svn-id: http://svn.code.sf.net/p/openmediavault/code/trunk@1530 3c3d7b80-5828-415e-9f61-280b98178fff