Add support for ordinal suffixes

[jsmecham]

Added support for ordinal suffixes (i.e. 1st, 2nd, 3rd, ...) on days of the month by specifying 'o' or 'O' in the format.

[asual]

This looks useful but I see two problems with it:

1. The plugin tries to mirror the Java date and number formatting APIs. This will introduce a difference.
2. Such feature needs to support localization. Even if you make it configurable I'm not sure that the logic will apply well for every language with it's specifics.

I'm sorry to say it but it will be better if you implement it in your app.