CRM-16373 - CRM_Core_Config_Variables should be strictly about data

CRM-16373 - CRM_Core_Config_Variables should be strictly about data

The distribution of variables and functions between `CRM_Core_Config` and
`CRM_Core_Config_Variables` seems pretty random.  In anticipation of
swapping out `CRM_Core_Config_Variables`, make a few changes:

 * Move various functions from `CRM_Core_Config_Variables` to BAOs (`provinceLimit, `countryLimit`, `defaultContactCountry`, `defaultContactCountryName`, `defaultCurrencySymbol`)
 * Put deprecated stubs in `CRM_Core_Config`
 * Move most variables from `CRM_Core_Config` to `CRM_Core_Config_Variables`.