Now the customize options will be stored in their own file (custom.el), which will remain unversioned to allow more flexibilit and machine-specific options.
Most of the options previously in the custom-set-variables call were moved to a theme named "config-base", which will be loaded on start. The options can be overriden by customize
custom-file will be loaded only if it exists, if it doesn't it will be created.
default custom themes will only be loaded if no theme was configured