refactor fluid layout to be more specific to not interfere with modal content while adding right sidebar option

lib/scaffolding.less

@@ -24,20 +24,28 @@ body {
 }
 
 // Fluid layouts (left aligned, with sidebar, min- & max-width content)
-.container-fluid {
+.fluid-container {
   position: relative;
   min-width: 940px;
   padding-left: 20px;
   padding-right: 20px;
   .clearfix();
-  > .sidebar {
-    float: left;
-    width: 220px;
-  }
-  // TODO in v2: rename this and .popover .content to be more specific
-  > .content {
-    margin-left: 240px;
-  }
+}
+// Sidebars (left and right options)
+.fluid-sidebar-left,
+.fluid-sidebar-right {
+  width: 220px;
+}
+.fluid-sidebar-left   { float: left; }
+.fluid-sidebar-right  { float: right; }
+// The main content area
+.fluid-content {
+  margin-left: 240px;
+}
+// Reverse layout for sidebar on right
+.fluid-container.reverse .fluid-content {
+  margin-left: 0;
+  margin-right: 240px;
 }