Rename s/Globalize.format()/Globalize.formatDate()

Closes gh-223
Update UMD according to umdjs/returnExports

umdjs/returnExports: https://github.com/umdjs/umd/blob/master/returnExports.js

Ref gh-222
Closes gh-221
Number: Create initial module

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.

Implement integer and fraction digits format.

Allow the following integer and fraction override options:
- Minimum integer digits `minimumIntegerDigits`;
- Minimum fraction digits `minimumFractionDigits`;
- Maximum fraction digits `maximumFractionDigits`;

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

Ref gh-200
Closes gh-209, gh-213
(fix) src/build/intro-number.js to use UMD returnExports
(fix) src/build/intro-number.js to use UMD returnExports
temp README
temp
Number: Implement significant digits format

Ref gh-200
Closes gh-214, gh-215