[packman] Account password limitations and HTTPS for PMBS

[Karl Cheng]

Hi everyone,

I tried signing up for an account on the Packman Build Service, but it
failed saying that my password contained "invalid characters". What
kind of passwords are accepted by the service?

Also, it seems that I cannot access PMBS without adding an HTTPS
security exception. Is there a reason for this? Thanks for answering.

- Karl Cheng (Qantas94Heavy)