Start work on better printing of package version changes
Use new-style string formatting
Align things correctly
Only use as much space as needed
index cannot be None in display_actions anyway, so make it required
Split the display information into four categories

Also add a little more whitespace, for readability
Left-align the versions

It makes them easier to read.
Remove the old package table
Keep a dictionary of Package objects
Add channel information to the installed listing
Get the index for remove if we are showing the channel urls
Show channel information with remove
Allow for no linked or unlinked packages
The Packages dict doesn't use .tar.bz2
Show channel information for updated and downgraded
Indent package plan information four spaces instead of two
Clean up some spacing

- Less space after the package name
- Less space around the arrow
- Two - in the arrow
- A colon after the package name
Left-align the versions
Update spacing everywhere
Always fetch the package metadata for remove

This is needed to get some of the information needed by the printing in the
plan module.