Rewrite of the escape helper.

It is simillar to the awful.util.escape now, using a table which we
could expand (and rename) with other unwated characters if it comes to
that. I saw awesome break on many occasions because of encoding
problems.

helpers.lua

@@ -101,15 +101,15 @@ end
 
 --{{{ Escape a string
 function escape(text)
-    if text then
-        text = text:gsub("&", "&")
-        text = text:gsub("<", "&lt;")
-        text = text:gsub(">", "&gt;")
-        text = text:gsub("'", "&apos;")
-        text = text:gsub("\"", "&quot;")
-    end
+    local xml_entities = {
+        ["\""] = "&quot;",
+        ["&"]  = "&amp;",
+        ["'"]  = "&apos;",
+        ["<"]  = "&lt;",
+        [">"]  = "&gt;"
+    }
 
-    return text
+    return text and text:gsub("[\"&'<>]", xml_entities)
 end
 -- }}}
 -- }}}