Add libphonenumber 'format' field support.

[dracos]

This stores the format/intlFormat given for each libphonenumber formatter in the stub country files, and adds a new NationallyPreferred formatter to use that infomation.

Fixes #78.

[coveralls]

Coverage decreased (-0.07%) to 99.901% when pulling fc48959 on dracos:78-store-format-field into 850ad31 on DrHyde:master.

[dracos]

The coverage drop is because every entry in the XML provides a format, but I left in the else code in case it did not. If it's okay to assume all entries will do so, then the else code can be dropped and that section simplified.

[dracos]

Now removed the 'else' case. I've defaulted to intlFormat given format() outputs with a +countycode, but note a few intlFormats are NA as they can't be called internationally. I don't know if you'd like something different done about them, but it does at least mean it won't output a number that wouldn't work (I imagine these are quite edge case anyway).

For #79 I'll work on adding separate new format_national and format_international functions to keep that independent.

[coveralls]

Coverage increased (+3.0e-05%) to 99.967% when pulling 1df809a on dracos:78-store-format-field into 850ad31 on DrHyde:master.

[coveralls]

Coverage increased (+3.0e-05%) to 99.967% when pulling 99eca0e on dracos:78-store-format-field into 850ad31 on DrHyde:master.

[coveralls]

Coverage increased (+3.0e-05%) to 99.967% when pulling a885e59 on dracos:78-store-format-field into 850ad31 on DrHyde:master.

[coveralls]

Coverage increased (+7.0e-05%) to 99.967% when pulling f5cca32 on dracos:78-store-format-field into 850ad31 on DrHyde:master.

[coveralls]

Coverage increased (+7.0e-05%) to 99.967% when pulling 6352192 on dracos:78-store-format-field into 850ad31 on DrHyde:master.

[DrHyde]

Sorry for taking ages to get back to you on this, Real Life intervened and then I massively slacked off over Christmas and New Year. I like the idea of storing the nationally preferred representation of a number and making it available. However, the format() method is documented as returning a number in E.123 format - see all the examples in section 2 of the standard. I think this would best be implemented as a formatter - see Number::Phone::Formatters and Number::Phone::Formatter::Raw for an example.

If this could be reworked into something like Number::Phone::Formatter::NationallyPreferred I'd be happy to merge it.

[dracos]

Okay, I've done that, it seems to work okay. I had to pass the object into the formatter, but kept the string argument for backwards compatibility, dos that make sense?

For the other PR that then depends upon this one (national formatting), I can add another formatter to return the national formatted number (Number::Phone::Formatter::National?), if that is okay with you, but I can't see how I can do the "pass in a country and have it pick national/international as appropriate", so that could instead be a utility function somewhere? It does seem like an obvious thing to want. Update: I've done that.

[coveralls]

Coverage decreased (-0.03%) to 99.937% when pulling da17163 on dracos:78-store-format-field into fdabfd2 on DrHyde:master.

[DrHyde]

Thanks!