Update TODO: Remove some things that we've done.

TODO

@@ -501,22 +501,6 @@ this approach works, it doesn't solve the MBR problem, so likely we'd
 have to write a library for that (or perhaps go back to sfdisk but
 using a very abstracted interface over sfdisk).
 
-qemu caching
-------------
-
-(Suggested by Paolo Bonzini and Kevin Wolf)
-
-Measure the effect of cache=none, cache=directsync,
-cache=writethrough, cache=writeback.
-
-It's doubtful that using cache=none is useful, since it disables the
-host cache making read-heavy workloads slower (they rely entirely on
-the smaller appliance kernel's cache).  And in libguestfs we don't
-necessarily care about ongoing data integrity while writing, as long
-as data is reliably written out when g.sync, g.shutdown or g.close
-return.  Also in libguestfs we effectively control the whole stack, so
-we can ensure write barriers happen when we want.
-
 virt-sparsify should use discard
 --------------------------------
 
@@ -562,8 +546,6 @@ virt-builder
 
  - how can we give users a shell for debugging purposes?
 
- - get parallel xzcat working properly
-
  - allow non-xz-compressed templates (faster)
 
  - let notes etc be localized, ie. notes[en]=...