jQuery Password Strength Meter and complex passwords

There’s a performance problem related to the Password Strength Meter and complex passwords. The more a password is complex, the more the script will take to process it. Since WordPress doesn’t explicitly say what is the actual limit of a password, the performance will get poorer and poorer until browsers will flag the script as “unresponsive”. In some cases, especially when the JS engine is not very efficient, this will crash the browser because the script will exhaust the available memory. The jQuery script makes use of regular expressions to check the complexity of a password. This approach has several disadvantages when passwords are complex, e.g. when they’re very long and with a combination of special characters, numbers and letters. People who want to use complex passwords have troubles with the automatic check performed by Password Strength Meter. Developers can disable this script, but normal users should have a flag they can set to disable this behavior. Otherwise we should set a limit for the passwords.