Update some stylesheets to use new page_stylesheet_link_tag helper

Now that we have this helper, we no longer need these stylesheets to
include a `body.controller-action` wrapper to scope all the styles!

Someday we should convert more of our stylesheets to this format,
instead of slamming them all into `application.sass` like we do now.
Ah, well!

app/assets/stylesheets/auth_users/edit.sass

@@ -1,6 +1,5 @@
 @import "../partials/clean/constants"
 
-body.auth_users-edit, body.auth_users-update
 .settings-form
 	border: 1px solid $module-border-color
 	background: $module-bg-color

app/assets/stylesheets/devise/sessions/new.sass

@@ -1,6 +1,5 @@
 @import "../../partials/clean/constants"
 
-body.devise-sessions, body.devise-sessions-new
 #title
 	text-align: center
 	font-size: 2.5rem

app/assets/stylesheets/fundraising/campaigns/show.css.sass

@@ -9,7 +9,7 @@ $outfit-banner-h-padding: 4px
 $outfit-banner-v-padding: 2px
 $outfit-banner-inner-width: $outfit-inner-width - (2 * $outfit-banner-h-padding)
 
-body.fundraising-campaigns
+body
   +campaign-progress
   color: $campaign-text-color
 

app/views/auth_users/edit.html.erb

@@ -126,5 +126,5 @@
 <% end %>
 
 <% content_for :stylesheets do %>
-  <%= stylesheet_link_tag "auth_users/edit" %>
+  <%= page_stylesheet_link_tag "auth_users/edit" %>
 <% end %>

app/views/devise/sessions/new.html.erb

@@ -66,5 +66,5 @@
 </div>
 
 <% content_for :stylesheets do %>
-  <%= stylesheet_link_tag "devise/sessions/new" %>
+  <%= page_stylesheet_link_tag "devise/sessions/new" %>
 <% end %>

app/views/fundraising/campaigns/show.html.haml

@@ -124,4 +124,4 @@
     Thank you!!
 
 - content_for :stylesheets do
-  = stylesheet_link_tag 'fundraising/campaigns/show'
+  = page_stylesheet_link_tag 'fundraising/campaigns/show'

app/views/fundraising/donations/show.html.haml

@@ -48,4 +48,4 @@
   = javascript_include_tag 'fundraising/donations/show', defer: true
 
 - content_for :stylesheets do
-  = stylesheet_link_tag 'fundraising/donations/show'
+  = page_stylesheet_link_tag 'fundraising/donations/show'