'check-icon' SASS/LESS variable for using a different icon font, or if FA's variables aren't included.

Author: Tim van der Horst

awesome-bootstrap-checkbox.less

@@ -3,6 +3,8 @@
 // --------------------------------------------------
 
 @font-family-icon: 'FontAwesome';
+@fa-var-check: "\f00c";
+@check-icon: @fa-var-check;
 
 .checkbox-variant(@parent, @color) {
   .@{parent} input[type="checkbox"]:checked + label,
@@ -67,7 +69,7 @@
 
     &:checked + label::after{
       font-family: @font-family-icon;
-      content: @fa-var-check;
+      content: @check-icon;
     }
 
     &:disabled + label{
@@ -196,7 +198,7 @@ input[type="checkbox"],
 input[type="radio"] {
   &.styled:checked + label:after {
     font-family: @font-family-icon;
-    content: @fa-var-check;
+    content: @check-icon;
   }
   & .styled:checked + label {
     &::before {

awesome-bootstrap-checkbox.scss

@@ -4,6 +4,8 @@
 
 
 $font-family-icon: 'FontAwesome' !default;
+$fa-var-check: "\f00c" !default;
+$check-icon: $fa-var-check !default;
 
 @mixin checkbox-variant($parent, $color) {
   #{$parent} input[type="checkbox"]:checked + label,
@@ -68,7 +70,7 @@ $font-family-icon: 'FontAwesome' !default;
 
     &:checked + label::after{
       font-family: $font-family-icon;
-      content: $fa-var-check;
+      content: $check-icon;
     }
 
     &:disabled + label{
@@ -198,7 +200,7 @@ input[type="checkbox"],
 input[type="radio"] {
   &.styled:checked + label:after {
     font-family: $font-family-icon;
-    content: $fa-var-check;
+    content: $check-icon;
   }
   & .styled:checked + label {
     &::before {