Support for Javascript in Themes (#2803).

If javascripts/theme.js is found in the theme directory, it will be automatically loaded on each page.

git-svn-id: svn+ssh://rubyforge.org/var/svn/redmine/trunk@4558 e93f8b46-1217-0410-a6f0-8f06a7374b81

app/views/layouts/base.rhtml

@@ -9,6 +9,7 @@
 <%= stylesheet_link_tag 'application', :media => 'all' %>
 <%= stylesheet_link_tag 'rtl', :media => 'all' if l(:direction) == 'rtl' %>
 <%= javascript_include_tag :defaults %>
+<%= heads_for_theme %>
 <%= heads_for_wiki_formatter %>
 <!--[if IE]>
     <style type="text/css">