prevent horizontal misalignment inside modal on odd page width, fixes #414

dist/css/bootstrap2/bootstrap-switch.css

@@ -59,6 +59,7 @@
   text-align: left;
   overflow: hidden;
   line-height: 8px;
+  z-index: 0;
   -webkit-user-select: none;
   -moz-user-select: none;
   -ms-user-select: none;

dist/css/bootstrap3/bootstrap-switch.css

@@ -30,6 +30,7 @@
   text-align: left;
   overflow: hidden;
   line-height: 8px;
+  z-index: 0;
   -webkit-user-select: none;
   -moz-user-select: none;
   -ms-user-select: none;

src/less/bootstrap2/bootstrap-switch.less

@@ -11,6 +11,7 @@
   text-align: left;
   overflow: hidden;
   line-height: 8px;
+  z-index: 0;
   .user-select(none);
   vertical-align: middle;
   .transition(~"border-color ease-in-out .15s, box-shadow ease-in-out .15s");

src/less/bootstrap3/bootstrap-switch.less

@@ -11,6 +11,7 @@
   text-align: left;
   overflow: hidden;
   line-height: 8px;
+  z-index: 0;
   .user-select(none);
   vertical-align: middle;
   .transition(~"border-color ease-in-out .15s, box-shadow ease-in-out .15s");