[Issue 72] phone number format

[Samuel Erdtman]

I have been looking into the telephone number formatting issue a bit
since last week and there is a lot to read, here follows a VERY short
summary.

E.164 (http://www.itu.int/rec/T-REC-E.164/en), seems like a good
format for describing international numbers
E.123 (http://www.itu.int/rec/T-REC-E.123/en), has formatting
guidelines for both international and national numbers.
PABX, a format used for some business telephone systems, I don't know
how common it is.
RFC3966 (http://www.ietf.org/rfc/rfc3966.txt), uri for telephone
numbers, it is closely related to E.164

One of the harder parts with defining a common numbering format for
all phone numbers is that legacy phone numbers might need to be
reformatted. Further both total length and area code length can vary
between countries and regions.

Google has an opens source library
(http://code.google.com/p/libphonenumber/) used by the android phone
for parsing, formatting, storing and validating phone numbers. This
library has support for E.164, E123, and RFC3966.

Thoughts?

Cheers
//Samuel