Refactor setup.sh (symlinks creation), import chatzilla and venkman strings

Refactor setup.sh
* Create two functions to checkout Silme and create symlinks
* Refactor symlinks creation using an array for branches
* Move symlink creation after repository checkout

Add Chatzilla and Venkman (issue #73)
* setup.sh: add chatzilla and venkman checkout+symlinks
* glossaire.sh: update chatzilla and venkman repos