Fix lvcreate invocation for snapshots.
Use "-K" and "--yes" when (de)activating logical volumes.

Because we really mean it.
Remove encoding of LVM2 names.
Remove "no-block" option of EmptyDevice.

It was broken in that the corresponding job would be removed as soon
as "pvmove -b" would finish.
Redefine logical volume types.
New "options" treatment in the D-Bus API.

- A "options" argument is now intended to pass additional options to
  the lvm2 commands that are spawened, and we only include it for
  operations that have a lot of options.  For example, Rename has no
  options anymore, but CreateThinVolume now has.

- Some arguments like extent size and stripe configuration
  should be done with options, but have been removed for now.

- The "wipe" option is now passed as a regular argument.