Replaces the obsolete robots.txt with a cached action (#2491).

git-svn-id: svn+ssh://rubyforge.org/var/svn/redmine/trunk@2319 e93f8b46-1217-0410-a6f0-8f06a7374b81

app/views/welcome/robots.rhtml

@@ -0,0 +1,9 @@
+User-agent: *
+<% @projects.each do |p| -%>
+Disallow: /projects/<%= p.to_param %>/repository
+Disallow: /projects/<%= p.to_param %>/issues
+Disallow: /projects/<%= p.to_param %>/activity
+<% end -%>
+Disallow: /issues/gantt
+Disallow: /issues/calendar
+Disallow: /activity