mod: code cleanup for readers

closes #26

pdfreader.lua

@@ -14,13 +14,5 @@ end
 -- open a PDF file and its settings store
 function PDFReader:open(filename, password)
 	self.doc = pdf.openDocument(filename, password or "")
-	if self.doc ~= nil then
-		self.settings = DocSettings:open(filename)
-		local gamma = self.settings:readsetting("gamma")
-		if gamma then
-			self.globalgamma = gamma
-		end
-		return true
-	end
-	return false
+	return self:loadSettings(filename)
 end