Plaintext paswords require a pw change

[Volte6]

Description

If a user record is set to a plaintext password, they will be required to change it before they can do anything else.

This is specifically applicable to the default admin login, but in case user files are manually edited to change the password in the future.

Changes

• Disallow any commands other than password if they have a plaintext password
• Suppress "on login commands" if plaintext password
• Remove previous temporary measure allowing only admin to have a plaintext password