Modify Accountcode

I've added support to apply regex code to accountcodes before rating.  This only applies during the rating process and is necessary for those that store extra data in their accountcodes.  It does not come populated in the configuration by default as it shouldn't be used unless necessary.

cdr_regex_accountcode

Example: -\d\d\d\d$

This will strip a taililng hyphen and 4 digits.