Comment 5 for bug 1050586

The old README file refered to a version of Listaller before it was rewritten in Vala, so it was completely useless... Funny, I thought 0.5.5 already had the updated version ;-)
I don't have much influence on cmake messages, but it's kinda obvious that you will need the development files to compile an application ;-)
I suppose the "patches" you're talking about were taken from some of the bug reports? You might want to try the Git snapshot, although you will have to compile a development version of PackageKit too then.
There will be a newer Listaller release together with PackageKit 0.8.4 - my work on PackageKit and AppStream/OpenSUSE blocked Listaller a little, but you can be confident there will be a release in next ~3weeks. (and after that we switch to a release cycle in sync with PackageKit and GNOME)

The prepare script is just to set up cmake quickly - usually you shouldn't use it and run cmake directly, which causes much less errors and allows further optimizations. That's why I thing removing it for 0.5.6 is sane.
(I'm also no bash expert, so I can't make it completely error-proof)

Btw: You'll also need some other stuff like GPGMe development files. On Quantal or Debian Wheezy, just execute
sudo apt-get build-dep listaller
to get them all. You can also see a list of build-dependencies here: http://packages.debian.org/source/sid/listaller

So, this should really be enough information to make it possible for you to compile the project :-) - Oh, and if you want LiBuild too: Don't forget to enabled it with -DLIBUILD=ON.