Add a Currency field type

[zackkatz]

Number formatting is one thing…currency is another!

Currencies need to handle different challenges:

• Numerical sorting
• Symbol handling
  • Symbol before or after
  • Space between symbol and price or not "£ 100" vs "$100"
• Decimal handling
• Thousand separator

[mrcasual]

A good reading: https://gist.github.com/rgs/6509585