Fix #349. Now the command "wall" work properly.
The bug comes from a poor implementation of VTE in GTK2.
This bug does not exist in GTK3.

Guake now has a dependency on the library libutempter.
Add some load tests for the lib libutempter. libutempter is now optional.
Normalization of sources
Merge pull request #403 from ImmortalPC/master

Fix #349. Now the command "wall" work properly.