fix(layout): allow layout-align without cross-axis value

docs/app/js/app.js

@@ -633,7 +633,8 @@ function($scope, $attrs, $location, $rootScope) {
     direction: 'row'
   };
   $scope.layoutAlign = function() {
-    return $scope.layoutDemo.mainAxis + ' ' + $scope.layoutDemo.crossAxis;
+    return $scope.layoutDemo.mainAxis +
+     ($scope.layoutDemo.crossAxis ? ' ' + $scope.layoutDemo.crossAxis : '')
   };
 }])
 

docs/app/partials/layout-alignment.tmpl.html

@@ -79,6 +79,7 @@
     <div>
       <md-subheader>Alignment in Perpendicular Direction ({{layoutDemo.direction == 'column' ? 'horizontal' : 'vertical'}})</md-subheader>
       <md-radio-group ng-model="layoutDemo.crossAxis">
+        <md-radio-button value=""><em>none</em> (use default)</md-radio-button>
         <md-radio-button value="start">start</md-radio-button>
         <md-radio-button value="center">center</md-radio-button>
         <md-radio-button value="end">end</md-radio-button>

src/core/services/layout/layout.js

@@ -433,8 +433,8 @@
       cross: "stretch"
     };
 
-    var values = (value || "").replace(WHITESPACE, "-").split("-");
-    if ( values.length == 3 ) {
+    var values = (value || "").toLowerCase().replace(WHITESPACE, "-").split("-");
+    if ( values[0] === "space" ) {
       values = [ values[0]+"-"+values[1],values[2] ];
     }