enforce a configurable minimum password length when registering

customize.dist/application_config.js

@@ -49,6 +49,8 @@ define(function() {
         users.
     */
     config.loginSalt = '';
+    config.minimum_password_length = 8;
+
     config.badStateTimeout = 30000;
 
     config.applicationsIcon = {

customize.dist/translations/messages.js

@@ -409,6 +409,8 @@ define(function () {
     out.register_importRecent = "Import pad history (Recommended)";
     out.register_acceptTerms = "I accept <a href='/terms.html' tabindex='-1'>the terms of service</a>";
     out.register_passwordsDontMatch = "Passwords do not match!";
+    out.register_passwordTooShort = "Passwords must be at least {0} characters long.";
+
     out.register_mustAcceptTerms = "You must accept the terms of service.";
     out.register_mustRememberPass = "We cannot reset your password if you forget it. It's very important that you remember it! Please check the checkbox to confirm.";