function number (list, path, options) {
	this._nativeType = Number;
	this._fixedSize = 'small';
	this._underscoreMethods = ['format'];
	this.formatString = (options.format === false) ? false : (options.format || '0,0[.][000000000000]');
	if (this.formatString && typeof this.formatString !== 'string') {
		throw new Error('FieldType.Number: options.format must be a string.');
	}
	number.super_.call(this, list, path, options);
}
Number FieldType Constructor
@extends Field
@api public