Custom translation for module

Custom translation without overwrite vtiger core files, for all modules defined in languages/custom/language/module.php file(s)

1/ You need to create a /custom directory in /languages directory

2/ Then create $language (en_us, de_de, ....) sub-directory

3/ Create a tranlation file like Accounts.php in languages/custom/en_us/ directory and define new tranlation or overwrite existing translations keys.

This small change will keep original Vtiger language file and allow users to upgrade Vtiger version without lossing own translaction.