PS:
I like Synaptic, a GUI for the package management. It automatically set
up an upgrade history. You manually can set up a history when using apt,
however, Synaptic is very comfortable.
A history provides information this way:
package_name (1.11.4) to 1.12.0
Note, for the "standard repository" 1.11.4 is replaced by 1.12.0 too, so
you can't simply downgrade using the same repository. You need another
repository or to keep packages.