(fix) save parentPath
fix(World group type): remove the children field

According to the discussion with Santiago:
- Organizations are not children of World. Organisations have no parent

Chat log:
https://monimus.hipchat.com/history/room/269039/2013/11/30?q=Organizations+are+not+children#02:30:10
Merge pull request #68 from mykabam/improve-world-group-type

fix(World group type): remove the children field
Merge branch 'acl' of github.com:mykabam/kabam-kernel into acl
feat(groups): add UserGroup group type for rootGroup
feat(model-loader): support for adding mongoose plugins
Merge branch 'acl'
chore(package): bump to 0.3.8
chore(core/model-loader): jshint fixes
feat(groups): personal user group
fix(User.signUp): search for World group type
chore(auth.api.test): replace throw with done
feat(User.signUp): automatically create rootGroup
fix(group-manager): add forgotted callback call
fix(group-factory): initial fix for restify read permissions
chore(group-manager): temporarily disable REST api for guests
fix(group-manager): don't leak internal errors to public
feat(logging): use info as default level
chore(group-manager.test): comment out wrong test
chore(group-rest-api.test): remove uneeded tests