-background to -bg on tooltip and popover vars

docs/assets/css/bootstrap.css

@@ -4399,9 +4399,9 @@ button.close {
   border-radius: 6px;
   -webkit-box-shadow: 0 5px 10px rgba(0, 0, 0, 0.2);
           box-shadow: 0 5px 10px rgba(0, 0, 0, 0.2);
-  -webkit-background-clip: padding-box;
-     -moz-background-clip: padding;
-          background-clip: padding-box;
+  background-clip: padding-box;
+  -webkit-bg-clip: padding-box;
+     -moz-bg-clip: padding;
 }
 
 .popover.top {

less/popovers.less

@@ -12,9 +12,9 @@
   max-width: 276px;
   padding: 1px;
   text-align: left; // Reset given new insertion method
-  background-color: @popover-background;
-  -webkit-background-clip: padding-box;
-     -moz-background-clip: padding;
+  background-color: @popover-bg;
+  -webkit-bg-clip: padding-box;
+     -moz-bg-clip: padding;
           background-clip: padding-box;
   border: 1px solid #ccc;
   border: 1px solid rgba(0,0,0,.2);
@@ -37,8 +37,8 @@
   font-size: 14px;
   font-weight: normal;
   line-height: 18px;
-  background-color: @popover-title-background;
-  border-bottom: 1px solid darken(@popover-title-background, 5%);
+  background-color: @popover-title-bg;
+  border-bottom: 1px solid darken(@popover-title-bg, 5%);
   border-radius: 5px 5px 0 0;
 
   &:empty {

less/tooltip.less

@@ -27,7 +27,7 @@
   color: @tooltip-color;
   text-align: center;
   text-decoration: none;
-  background-color: @tooltip-background;
+  background-color: @tooltip-bg;
   border-radius: @border-radius-base;
 }
 

less/variables.less

@@ -258,14 +258,14 @@
 // Tooltips and popovers
 // -------------------------
 @tooltip-color:               #fff;
-@tooltip-background:          rgba(0,0,0,.9);
+@tooltip-bg:                  rgba(0,0,0,.9);
 @tooltip-arrow-width:         5px;
-@tooltip-arrow-color:         @tooltip-background;
+@tooltip-arrow-color:         @tooltip-bg;
 
-@popover-background:          #fff;
+@popover-bg:                  #fff;
 @popover-arrow-width:         10px;
 @popover-arrow-color:         #fff;
-@popover-title-background:    darken(@popover-background, 3%);
+@popover-title-bg:            darken(@popover-bg, 3%);
 
 // Special enhancement for popovers
 @popover-arrow-outer-width:   (@popover-arrow-width + 1);