- Added file headers.
- Moved core provider impl to separate package.
- Added unimplemented exchange provider (based on IMF data).
Merge pull request #3 from clanie/master

BigDecimalAmount comparison functions, some todos added.
Merge branch 'master' of https://github.com/JavaMoney/javamoney.git
- Added input checks for numbers.
- Added input checks for currency mismatch.
- Implemented getAdjusted.
Added Claus Nielsen to the contributers list.
Fixed bug in BigDecimalAmount.checkAmountParameter and made checkNumber() private.