fix min-width media queries

Author: marcosmoura

src/components/mdLayout/mdLayout.scss

@@ -175,10 +175,6 @@ $sizes: (8, 16, 24, 40);
   .md-hide-#{$size} {
     display: none;
   }
-
-  .md-hide-#{$size}-and-up {
-    display: none;
-  }
 }
 
 @include layout-xlarge {
@@ -201,22 +197,18 @@ $sizes: (8, 16, 24, 40);
   @include breakpoint-layout(xsmall);
 }
 
-@include layout-xlarge-and-up {
-  @include breakpoint-layout(xlarge);
-}
-
 @include layout-large-and-up {
-  @include breakpoint-layout(large);
+  @include breakpoint-layout(large-and-up);
 }
 
 @include layout-medium-and-up {
-  @include breakpoint-layout(medium);
+  @include breakpoint-layout(medium-and-up);
 }
 
 @include layout-small-and-up {
-  @include breakpoint-layout(small);
+  @include breakpoint-layout(small-and-up);
 }
 
 @include layout-xsmall-and-up {
-  @include breakpoint-layout(xsmall);
+  @include breakpoint-layout(xsmall-and-up);
 }

src/components/mdLayout/mdLayout.vue

@@ -119,7 +119,11 @@
 
         if (this[name]) {
           if (typeof this[name] === 'boolean') {
-            object[prop + size] = true;
+            if (!this[name]) {
+              object[prop + size + '-none'] = true;
+            } else {
+              object[prop + size] = true;
+            }
           } else {
             object[prop + size + '-' + this[name]] = true;
           }

src/core/stylesheets/mixins.scss

@@ -75,9 +75,3 @@
     @content;
   }
 }
-
-@mixin layout-xlarge-and-up {
-  @media (min-width: #{$breakpoint-large - 16px}) {
-    @content;
-  }
-}