implement File finding

lib/gollum/file.rb

@@ -1,6 +1,6 @@
 module Gollum
   class File
-    attr_accessor :wiki
+    attr_accessor :wiki, :blob
 
     # Initialize a file.
     #
@@ -10,5 +10,28 @@ module Gollum
     def initialize(wiki)
       self.wiki = wiki
     end
+
+    # The raw contents of the page.
+    #
+    # Returns the String data.
+    def raw_data
+      self.blob.data rescue nil
+    end
+
+    # Find a file in the given Gollum repo.
+    #
+    # name    - The full String path.
+    # version - The String version ID to find.
+    #
+    # Returns a Gollum::File or nil if the file could not be found.
+    def find(name, version)
+      commit = self.wiki.repo.commit(version)
+      if blob = commit.tree / name
+        self.blob = blob
+        self
+      else
+        nil
+      end
+    end
   end
 end