Move setting of the core namespace to after default_folders are loaded
Move setting of the core namespace to after default_folders are loaded

Previously, the core namespace was created before default_folders was
loaded. This meant that it was impossible to tell 'core' to use different
dirs for 'js', 'css', or 'img' using the 'js_dir', 'css_dir' or 'img_dir'
config keys. However, setting these keys under the 'paths' config key for
the 'core' namespace *would* still work.

canton7/fuelphp-casset