BUG FIXES:
- resource/random_password: Prevent crash when length is less than 0 (#129, #181, #200, #233).
- resource/random_string: Prevent crash when length is less than 0 (#129, #181, #200, #233).
- resource/random_password: Prevent confusing inconsistent result error when length is 0 (#222, #233).
- resource/random_string: Prevent confusing inconsistent result error when length is 0 (#222, #233).