All EU Tax Zones plus Norway, Iceland, Switzerland and Sout Africa
Merge pull request #3 from dwkitchen/tax-zones

All EU Tax Zones plus Norway, Iceland, Switzerland and Sout Africa
Follow symfony docblock convention, make Currency setters fluid.
Remove the rounding step, it doesn't need to exist on the currency level.
Rename getCurrency() to get() and getCurrencies() to getAll(), to match Symfony naming guidelines.
Rename the code to currencyCode, and the number to numericCode, to match ISO standard and Java's Currency class.
Rename CurrencyManager to DefaultCurrencyManager, move currency definitions to YAML.
Coding standard fixes (brace style).
Add the price object.
Update README.md
Typehint the currency by interface.
Add the formatting section to the readme
Add a __toString() method to the default Currency class.
Add a method for converting the price to another currency, expand README.
Fix the stripping of trailing zeroes to ignore non-decimal numbers.
Rename decimals to fraction digits, to match naming in other places (currency classes in other languages, NumberFormatter, Symfony).
Add translation support for currency names and symbols.

- Rename currency.yml to currencies.yml
- Re-export currencies.yml from the ISO and CLDR data.
- Make sure that the symbols and names in currencies.yml are en_US.
- Update README.
Add the script that generates the yaml data.
Remove the zone yml files and David from the maintainers, that will be added to a new tax library.
Fix currency ordering in currencies.yml, remove a few 'special currencies' that were accidentally added, update export script.