Implement the ability to store uploads on a per-page basis

Storing all uploaded files in a single directory kinda sucks when you've got
a largish wiki, or the possibility of filename collisions.  With this patch,
though, you can set `:per_page_uploads => true` in your wiki settings and
have the file uploaded to a directory named for the page you were on when
you clicked 'Upload'.

lib/gollum/app.rb

@@ -163,7 +163,7 @@ module Precious
         tempfile = params[:file][:tempfile]
       end
 
-      dir = 'uploads'
+      dir = wiki.per_page_uploads ? params[:upload_dest] : 'uploads'
       ext = ::File.extname(fullname)
       format = ext.split('.').last || 'txt'
       filename = ::File.basename(fullname, ext)
@@ -173,7 +173,7 @@ module Precious
       head = wiki.repo.head
 
       options = {
-        :message => "Uploaded file to uploads/#{reponame}",
+        :message => "Uploaded file to #{dir}/#{reponame}",
         :parent => wiki.repo.head.commit,
       }
       author = session['gollum.author']
@@ -444,6 +444,10 @@ module Precious
         @page = page
         @name = name
         @content  = page.formatted_data
+        @upload_dest = settings.wiki_options[:allow_uploads] ?
+                         (settings.wiki_options[:per_page_uploads] ?
+                            @name : 'uploads'
+                         ) : ''
 
         # Extensions and layout data
         @editable = true

lib/gollum/public/gollum/javascript/gollum.dialog.js

@@ -99,6 +99,8 @@
 
       html += '<form method=post enctype="multipart/form-data" ' +
         'action="' + action + '" ' + 'id="' + id + '">';
+      html += '<input type="hidden" name="upload_dest" value="' +
+        uploadDest + '">';
       html += '<input type=file name="' + name + '">';
       html += '</form>';
 

lib/gollum/public/gollum/javascript/gollum.js

@@ -155,7 +155,7 @@ $(document).ready(function() {
         fields: [
           {
             type:   'file',
-            context: 'Your uploaded file will be accessible at /uploads/[filename]'
+            context: 'Your uploaded file will be accessible at /'+uploadDest+'/[filename]'
           }
         ],
         OK: function( res ) {

lib/gollum/templates/layout.mustache

@@ -16,6 +16,7 @@
       var baseUrl = '{{base_url}}';
       {{#page}}
       var pageFullPath = '{{url_path_display}}';
+      var uploadDest   = '{{upload_dest}}';
       {{/page}}
   </script>
   <script type="text/javascript" src="{{base_url}}/javascript/jquery-1.7.2.min.js"></script>

lib/gollum/views/page.rb

@@ -42,6 +42,10 @@ module Precious
       def allow_uploads
         @allow_uploads
       end
+      
+      def upload_dest
+        @upload_dest
+      end
 
       def has_header
         @header = (@page.header || false) if @header.nil?