studio - link wiring and spot styling changes for new nav/soft landing/settings work

cms/static/sass/_index.scss

@@ -36,7 +36,9 @@
       color: $gray-d2;
     
       header {
-
+        border: none;
+        padding-bottom: 0;
+        margin-bottom: 0;
       }
 
       h1, h2, h3, h4, h5, h6 {

cms/templates/login.html

@@ -9,7 +9,7 @@
   <section class="content">
     <header>
       <h1 class="title title-1">Sign into edX Studio</h1>
-      <a href="" class="action action-signin">Don't have a Studio Account? Sign up!</a>
+      <a href="${reverse('signup')}" class="action action-signin">Don't have a Studio Account? Sign up!</a>
     </header>
 
     <article class="content-primary" role="main">

cms/templates/settings.html

@@ -76,7 +76,7 @@ from contentstore import utils
               <input type="text" class="long" id="course-name" value="[Course Name]" disabled="disabled" />
             </li>
           </ol>
-          <span class="tip tip-stacked">These are used in <a href="${utils.get_lms_link_for_about_page(course_location)}" />your course URL</a>, and cannot be changed</span>
+          <span class="tip tip-stacked">These are used in <a rel="external" href="${utils.get_lms_link_for_about_page(course_location)}" />your course URL</a>, and cannot be changed</span>
         </section>
 
         <hr class="divide" />

cms/templates/signup.html

@@ -10,7 +10,7 @@
   <section class="content">
     <header>
       <h1 class="title title-1">Sign Up for edX Studio</h1>
-      <a href="" class="action action-signin">Already have a Studio Account? Sign in</a>
+      <a href="${reverse('login')}" class="action action-signin">Already have a Studio Account? Sign in</a>
     </header>
 
     <p class="introduction">Ready to start creating online courses? Sign up below and start creating your first edX course today.</p>