Number: Create initial public API
Number: Create initial format function
Number: Decouple format setup from execution

Number format setup is performed by numberFormatProperties(). Number
format execution is performed by numberFormat(). This arrangement allows
subsequent setup caching for improved performance. Yet this
implementation doesn't follow ECMA-402, it's been based on
Intl.NumberFormat instance properties.
Number: Format options for integer and fraction

Allow Globalize.format() to override locale for the following options:
- Minimum integer digits `minimumIntegerDigits`;
- Minimum fraction digits `minimumFractionDigits`;
- Maximum fraction digits `maximumFractionDigits`;
Number: Allow different rounding mode

Globalize.format() accepts the following `round` options:
- "ceil";
- "floor";
- "round" (default);
- "truncate";