fix($mdConstant): fix overlapping in media-queries

Fixes #3423.
Closes #3451.

Author: gkalpak

src/core/util/constant.js

@@ -37,11 +37,11 @@ function MdConstantFactory($$rAF, $sniffer) {
       ANIMATION_DIRECTION: vendorProperty('animationDirection')
     },
     MEDIA: {
-      'sm': '(max-width: 600px)',
+      'sm': '(max-width: 599px)',
       'gt-sm': '(min-width: 600px)',
-      'md': '(min-width: 600px) and (max-width: 960px)',
+      'md': '(min-width: 600px) and (max-width: 959px)',
       'gt-md': '(min-width: 960px)',
-      'lg': '(min-width: 960px) and (max-width: 1200px)',
+      'lg': '(min-width: 960px) and (max-width: 1199px)',
       'gt-lg': '(min-width: 1200px)'
     },
     MEDIA_PRIORITY: [