Use link_color var more often

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

app/assets/stylesheets/generic/common.scss

@@ -60,7 +60,7 @@ pre {
 
 .dropdown-menu > li > a:hover,
 .dropdown-menu > li > a:focus {
-  background: #29b;
+  background: $bg_style_color;
   color: #FFF
 }
 

app/assets/stylesheets/sections/nav.scss

@@ -64,7 +64,7 @@
             left: 50%;
             width: 0;
             height: 0;
-            border-color: transparent transparent #29b transparent;
+            border-color: transparent transparent $link_color transparent;
             border-style: solid;
             border-width: 6px;
             margin-left: -6px;

app/assets/stylesheets/sections/projects.scss

@@ -85,7 +85,7 @@
 
   .btn {
     background: none;
-    color: #29b;
+    color: $link_color;
 
     &.active {
       color: #333;