Clean up NUX a bit on Diffusion

Summary: Just some cleanup. Make sure action-bar has consistent space if locate is there or not, hide tabs if repository has no content. Use clone or checkout language depending on SCM. Fixes T12915.

Test Plan:
Test git, hg, svn blank states.

{F5042707}

Reviewers: epriestley

Reviewed By: epriestley

Subscribers: Korvin

Maniphest Tasks: T12915

Differential Revision: https://secure.phabricator.com/D18208

resources/celerity/map.php

@@ -75,7 +75,7 @@ return array(
     'rsrc/css/application/diffusion/diffusion-readme.css' => '419dd5b6',
     'rsrc/css/application/diffusion/diffusion-repository.css' => 'ee6f20ec',
     'rsrc/css/application/diffusion/diffusion-source.css' => '750add59',
-    'rsrc/css/application/diffusion/diffusion.css' => '08991f7e',
+    'rsrc/css/application/diffusion/diffusion.css' => '8d01932f',
     'rsrc/css/application/feed/feed.css' => 'ecd4ec57',
     'rsrc/css/application/files/global-drag-and-drop.css' => '5c1b47c2',
     'rsrc/css/application/flag/flag.css' => 'bba8f811',
@@ -571,7 +571,7 @@ return array(
     'differential-revision-history-css' => '0e8eb855',
     'differential-revision-list-css' => 'f3c47d33',
     'differential-table-of-contents-css' => 'ae4b7a55',
-    'diffusion-css' => '08991f7e',
+    'diffusion-css' => '8d01932f',
     'diffusion-icons-css' => '0c15255e',
     'diffusion-readme-css' => '419dd5b6',
     'diffusion-repository-css' => 'ee6f20ec',