Update README.md; add VirtualBox as a dependency
roles/lemp: Add php5-intl to apt-get list

Add php5-intl to the list of packages to be installed as it is required in the fix Tatoeba/tatoeba2@f3d647f45088443eb27f1e42c5eaf18322283b1e
imoutu-devel/ansible: Split codebase role into multiple roles

The codebase role is now divided into 3 separate roles update_code,
setup_cakephp and setup_database so that the code can be updated
independently from github without having to re-create the database
roles/update_code/files: Create link "current" with relative path

Symbolic link "current" is now created with relative path to the
directory containing the latest code instead of absolute path
roles/setup_cakephp: Create links for cakephp configs with relative path

The symbolic links for core.php and database.php in app/config/ are now
created with relative paths to configs present in common/config
ansible/group_vars/all: Change default code directory to /vagrant/Tatoeba

Change the default code directory of VM in which the whole Tatoeba
code resides to '/vagrant/Tatoeba' in order to make use of vagrant's
"synced folders" feature to sync the VM's code to the current directory
(which contains the "Vagrantfile") of the host machine so that the
developer can edit the code from host machine itself
Merge branch 'master' of https://github.com/Tatoeba/admin