implement auto login and remember password

modules/core/ext/string.lua

@@ -10,5 +10,17 @@ function string:split(sep)
 end
 
 function string:starts(start)
-   return self:sub(1, #start) == start
+  return self:sub(1, #start) == start
 end
+
+function string.trim(str)
+  return str:match'^%s*(.*%S)' or ''
+end
+
+function toboolean(str)
+  str = string.trim(str)
+  if str == '1' or str == 'true' then
+    return true
+  end
+  return false
+end