Refactor glossaire and setup bash scripts

* Create functions to reuse code.
* Use "hg update -C" (--clean) instead of "hg update -c" (--check). I think it was the original idea too, since --clean let you ignore local changes. In my own VM mozilla-central was stuck because of a conflict, this should avoid this kind of problems.
* Use colors in console output to differentiate command output (no color), errors (red) and messages (green).
* Make setup.sh interruptible.
* Use $(var) instead of `var`.