Add @btn-color variable and use in buttons and carets; fixes dropup caret as well

docs/assets/css/bootstrap.css

@@ -1679,7 +1679,7 @@ input[type="button"].btn-block {
 }
 
 .btn {
-  color: #fff;
+  color: #ffffff;
   background-color: #a7a9aa;
   border-color: #a7a9aa;
 }
@@ -3245,9 +3245,12 @@ button.close {
 
 */
 
-.caret {
-  border-top-color: #fff;
-  border-bottom-color: #fff;
+.btn .caret {
+  border-top-color: #ffffff;
+}
+
+.dropup .btn .caret {
+  border-bottom-color: #ffffff;
 }
 
 .btn-group {
@@ -3344,19 +3347,10 @@ button.close {
   margin-left: 0;
 }
 
-.btn-large .caret {
-  margin-top: 6px;
-}
-
 .btn-large .caret {
   border-width: 5px;
 }
 
-.btn-mini .caret,
-.btn-small .caret {
-  margin-top: 8px;
-}
-
 .dropup .btn-large .caret {
   border-bottom-width: 5px;
 }

less/button-groups.less

@@ -3,9 +3,11 @@
 // --------------------------------------------------
 
 // Button carets
-.caret {
-  border-top-color: #fff;
-  border-bottom-color: #fff;
+.btn .caret {
+  border-top-color: @btn-color;
+}
+.dropup .btn .caret {
+  border-bottom-color: @btn-color;
 }
 
 // Make the div behave like a button
@@ -104,16 +106,9 @@
   margin-left: 0;
 }
 // Carets in other button sizes
-.btn-large .caret {
-  margin-top: 6px;
-}
 .btn-large .caret {
   border-width: 5px;
 }
-.btn-mini .caret,
-.btn-small .caret {
-  margin-top: 8px;
-}
 // Upside down carets for .dropup
 .dropup .btn-large .caret {
   border-bottom-width: 5px;

less/buttons.less

@@ -115,7 +115,7 @@ input[type="button"] {
 // --------------------------------------------------
 
 .btn {
-  color: #fff;
+  color: @btn-color;
   background-color: @btn-background;
   border-color: @btn-border;
   &:hover,

less/variables.less

@@ -82,6 +82,7 @@
 // Buttons
 // -------------------------
 
+@btn-color:                          #fff;
 @btn-background:                     #a7a9aa;
 @btn-border:                         @btn-background;