Number: Create initial public API

Ref gh-200
Number: Create initial format function

Ref gh-200, gh-213
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.

Ref gh-200, gh-213
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`;

Ref gh-200, gh-213
Number: Allow different rounding mode

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

Ref gh-200
Closes gh-213