Installing and Compiling GNU Octave 3.8.1 for Ubuntu 12.04 (32bits)

This is the first time that I have found a very comprehensible tutorial [1] on how to install and compile GNU Octave on Ubuntu. One of the most amazing new features is that versions 3.8.x are going to be released with a graphical user interface (GUI) as shown in Figure 1. In order to maintain a kind of register for, perhaps, further consultation, I have copied some descriptions of my terminal output: http://pastebin.com/CRG6GSEz

Figure 1. GUI for GNU Octave 3.8.1

Reference
[1] http://blogs.bu.edu/mhirsch/2013/12/compiling-octave-3-8/