Description:
------------
This is a feature request for the list-upgrades command to list more information:

(a) Currently installed version:
  This way I'll know exactly what's going on, what version
  will be upgraded, and what version it will be upgraded to.
  list-all provides this information.

(b) List both beta and stable versions (maybe alpha too):
  Regardless of preferred_state, if both stable and beta 
  versions are shown, I'll know exactly what's going on and 
  might choose beta over stable, or vice versa.

  Also, currently upgrades aren't listed as stable or beta
  while this information would be nice.  If my
  preferred_state is beta, I'd like to know if I'm about to
  upgrade to a beta or stable... same goes with alpha.

I believe both (a) and (b) are worthy features and will let the user know exactly what's going on, and make reading the package changelog that much more useful.

Lastly, (b) is a little tricky to output but I attempted to create a version below, and some of the information (version numbers and sizes) are made up.


Reproduce code:
---------------
// Assuming preferred_state = beta
pear list-upgrades

// Assuming preferred_state = stable
pear list-upgrades

Expected result:
----------------
Available Upgrades (preferred_state = beta):
============================================
Package       Beta*    Stable   Local    Size
DB            1.5.0RC1 1.4.0    1.2.0    65kB
PEAR_Info              1.0.6    1.0.5    6.2kB
PhpDocumentor          1.2.0    1.1.0    2410kB

Available Upgrades (preferred_state = stable):
==============================================
Package       Beta     Stable*  Local    Size
DB            1.5.0RC1 1.4.0    1.2.0    59kB
PEAR_Info              1.0.6    1.0.5    6.2kB
PhpDocumentor          1.2.0    1.1.0    2410kB


Actual result:
--------------
Available Upgrades (beta):
==========================
Package       Version  Size
DB            1.5.0RC1 65kB
PEAR_Info     1.0.6    6.2kB
PhpDocumentor 1.2.0    2410kB

Available Upgrades (stable):
============================
Package       Version  Size
DB            1.4.0    59kB
PEAR_Info     1.0.6    6.2kB
PhpDocumentor 1.2.0    2410kB