rename media query var to match /cc @cvrebert

scss/_variables.scss

@@ -42,6 +42,7 @@ $enable-rounded:             true !default;
 $enable-shadows:             false !default;
 $enable-gradients:           false !default;
 $enable-transitions:         true !default;
+$enable-hover-media-query:      false !default;
 
 
 // Component defaults
@@ -55,7 +56,6 @@ $spacer-y:                   $spacer !default;
 
 $border-width:               .0625rem !default;
 
-$use-hover-media-query:      false !default;
 
 // Typography
 //

scss/mixins/_hover.scss

 @mixin hover {
-  @if $use-hover-media-query {
+  @if $enable-hover-media-query {
     // See Media Queries Level 4: http://drafts.csswg.org/mediaqueries/#hover
     // Currently shimmed by https://github.com/twbs/mq4-hover-shim
     @media (hover: hover) {
@@ -12,7 +12,7 @@
 }
 
 @mixin hover-focus {
-  @if $use-hover-media-query {
+  @if $enable-hover-media-query {
     &:focus { @content }
     @include hover { @content }
   }
@@ -25,7 +25,7 @@
 }
 
 @mixin plain-hover-focus {
-  @if $use-hover-media-query {
+  @if $enable-hover-media-query {
     &,
     &:focus {
       @content
@@ -42,7 +42,7 @@
 }
 
 @mixin hover-focus-active {
-  @if $use-hover-media-query {
+  @if $enable-hover-media-query {
     &:focus,
     &:active {
       @content