[model] Make ability_test able to really send some constraint

It now uses the same syntax than in recipe description. Probably still a
lot of bugs to discover
[doc] Complete the first agent tutorial, using the new test features
[doc] Complete the second tutorial

Fix some issues after testing
Add some examples of control of the agent.
[compiler] Honor verbose switch

Add a verbose boolean state in universe, and only print 'information' if
it is turned on. The default behaviour is 'quiet'.
At hyperc level, pass the right value to universe, depending of the
command line switch
[model] Be quiet if not at least in debug mode.

While here, fix a typo
[model] Don't need to start ability_test in DEBUG_ALL mode

INFORMATION is largely enough