Renaming default.po to croogo.po

See: http://croogo.lighthouseapp.com/projects/32818/tickets/356-I18n-domain
Renaming locale folders as required by cakephp changes

See: cakephp/cakephp@c87b53a7d851fb1b6ecc098663c9479a7f79aab3
See: cakephp/cakephp@032704346a99c0daf31e4a95ed6d5bdcb36187e2
See: http://book.cakephp.org/2.0/en/appendices/2-3-migration-guide.html#i18n