/*
Check if center is valid and format it.

return: <Array|boolean> If center is valid, return [Lng, Lat] array. If center is invalid, return false.
function validateAndFormatCenter (center) {
		// [lng, lat]
		var defer = $q.defer();

		if (angular.isDefined(center)) {
			if (angular.isDefined(center.autodiscover) && center.autodiscover) {
				$window.navigator.geolocation.getCurrentPosition(function (position) {
					var coordinates = position.coords;

					defer.resolve([coordinates.longitude, coordinates.latitude]);
				}, function (error) {
					defer.resolve(false);
					// defer.reject(error);
				}, {
					enableHighAccuracy: true,
  				timeout: 5000,
  				maximumAge: 0
				});
			} else if (angular.isNumber(center.lat) && angular.isNumber(center.lng) && (center.lng > -180 || center.lng < 180) && (center.lat > -90 || center.lat < 90)) {
				defer.resolve([center.lng, center.lat]);
			} else if (angular.isArray(center) && center.length === 2 && angular.isNumber(center[0]) && angular.isNumber(center[1]) && (center[0] > -180 || center[0] < 180) && (center[1] > -90 || center[1] < 90)) {
				defer.resolve(center);
			} else {
				defer.resolve(false);
			}
		} else {
			defer.resolve(false);
		}

		return defer.promise;
	}