Merge branch 'mixin-cleanup' into 'master'

Mixin cleanup

* Remove old mixins
* add issue box shadow
* change color for network graph box

app/assets/stylesheets/generic/issue_box.scss

@@ -12,6 +12,7 @@
   margin:20px 0;
   background: #FFF;
   border: 1px solid #EEE;
+  @include box-shadow(0 1px 1px rgba(0, 0, 0, 0.05));
 
   &.issue-box-closed {
     border-color: #DA4E49;

app/assets/stylesheets/main/mixins.scss

@@ -41,31 +41,6 @@
  * Prefilled mixins
  * Mixins with fixed values
  */
-@mixin bg-light-gray-gradient {
-  background: #f1f1f1;
-  background-image: -webkit-gradient(linear, 0 0, 0 30, color-stop(0.066, #f5f5f5), to(#e1e1e1));
-  background-image: -webkit-linear-gradient(#f5f5f5 6.6%, #e1e1e1);
-  background-image: -moz-linear-gradient(#f5f5f5 6.6%, #e1e1e1);
-  background-image: -ms-linear-gradient(#f5f5f5 6.6%, #e1e1e1);
-  background-image: -o-linear-gradient(#f5f5f5 6.6%, #e1e1e1);
-}
-
-@mixin bg-gray-gradient {
-  background: #eee;
-  background-image: -webkit-gradient(linear, 0 0, 0 30, color-stop(0.066, #eee), to(#dfdfdf));
-  background-image: -webkit-linear-gradient(#eee 6.6%, #dfdfdf);
-  background-image: -moz-linear-gradient(#eee 6.6%, #dfdfdf);
-  background-image: -ms-linear-gradient(#eee 6.6%, #dfdfdf);
-  background-image: -o-linear-gradient(#eee 6.6%, #dfdfdf);
-}
-
-@mixin bg-dark-gray-gradient {
-  background: #eee;
-  background-image: -webkit-linear-gradient(#e9e9e9, #d7d7d7);
-  background-image: -moz-linear-gradient(#e9e9e9, #d7d7d7);
-  background-image: -ms-linear-gradient(#e9e9e9, #d7d7d7);
-  background-image: -o-linear-gradient(#e9e9e9, #d7d7d7);
-}
 
 @mixin shade {
   @include box-shadow(0 0 3px #ddd);

app/assets/stylesheets/sections/graph.scss

 .project-network {
-  border: 1px solid #aaa;
-  padding: 1px;
+  border: 1px solid #CCC;
 
   .tip {
     color: #888;
     font-size: 14px;
     padding: 10px;
     border-bottom: 1px solid #bbb;
-    @include bg-gray-gradient;
+    background: #EEE;
   }
 
   .network-graph {
-    background: #f1f1f1;
+    background: #FFF;
     height: 500px;
     overflow-y: scroll;
     overflow-x: hidden;