Create schema: dmedia/drive and dmedia/partition.

This is related to:
    lp:692449
    lp:714941

I've created a simple udisks wrapper in lp:~david4dev/dmedia/udisks .

We need a way to store drive and partition information for imports and file stores. IMO the best way to do this is through separate schema for partition and drive. That way imports and file stores could simply link to the document for the partition (which itself could link to the drive).

I suggest something like this for the partition schema:

    >>> doc = {
    ... '_id': '1a123456-ab12-1ab2-12a3-1abcd12ab1a2',
    ... 'type': 'dmedia/partition',
    ... 'size':140123456789,
    ... 'label':'Data',
    ... 'partition_label':'',
    ... 'fs':'ext4',
    ... 'drive':'irojEJDwkdmsoJQDIWDKOW'
    ... }

Where _id is the UUID (http://hal.freedesktop.org/docs/udisks/Device.html#Device:IdUuid). size is the number of bytes capacity (http://hal.freedesktop.org/docs/udisks/Device.html#Device:PartitionSize). label is the label that you see in the file manager (http://hal.freedesktop.org/docs/udisks/Device.html#Device:IdLabel) and partition_label is the partition label (http://hal.freedesktop.org/docs/udisks/Device.html#Device:PartitionLabel) which are actually different things. fs is the filesystem type (http://hal.freedesktop.org/docs/udisks/Device.html#Device:IdType). drive links to the _id of the drive.

Something like this for the drive schema:

    >>> doc = {
    ... '_id': 'irojEJDwkdmsoJQDIWDKOW',
    ... 'type': 'dmedia/device',
    ... 'size':238123456789,
    ... 'serial':'3MH05AVA',
    ... 'wwn':'50014ee0016eb572',
    ... 'vendor':'BELKIN',
    ... 'model':'ST910021AS',
    ... 'revision':'3.07'
    ... }

Where _id is a random id. size is the drive size in bytes. serial is the drive serial (http://hal.freedesktop.org/docs/udisks/Device.html#Device:DriveSerial). wwn is the dive World Wide Number (http://hal.freedesktop.org/docs/udisks/Device.html#Device:DriveWwn). vendor is the drive vendor (http://hal.freedesktop.org/docs/udisks/Device.html#Device:DriveVendor). model is the drive model (http://hal.freedesktop.org/docs/udisks/Device.html#Device:DriveModel). revision is the drive revision (http://hal.freedesktop.org/docs/udisks/Device.html#Device:DriveRevision).

So the filestore and import schema can have a 'partition' key which has the value of the _id or the partition document.

Does this make sense?