[skip ci] fix tooltip alignment and add border color

app/assets/stylesheets/framework/avatar.scss

@@ -97,7 +97,7 @@
 .avatar-counter {
   background-color: $gray-darkest;
   color: $white-light;
-  border: 1px solid $white-light;
+  border: 1px solid $avatar-counter-border-color;
   border-radius: 1em;
   font-family: $regular_font;
   font-size: 9px;

app/assets/stylesheets/framework/lists.scss

@@ -257,11 +257,11 @@ ul.controls {
 
     .author_link {
       display: inline-block;
-      vertical-align: middle;
 
       .avatar-inline {
         margin-left: 0;
         margin-right: 0;
+        margin-bottom: 0;
       }
     }
   }

app/assets/stylesheets/framework/variables.scss

@@ -437,6 +437,7 @@ $help-shortcut-header-color: #333;
 $issues-today-bg: #f3fff2;
 $issues-today-border: #e1e8d5;
 $compare-display-color: #888;
+$avatar-counter-border-color: #e6e6e6;
 
 /*
 * jQuery UI

app/assets/stylesheets/pages/issuable.scss

@@ -485,8 +485,9 @@
     .avatar-counter {
       display: inline-block;
       vertical-align: middle;
-      // margin-top: 1px;
-      min-width: 18px;
+      min-width: 16px;
+      line-height: 14px;
+      height: 16px;
     }
 
     .wide-counter {