Minor other alterations that relate to above as well.
Also added the PanicAlertT version of alerts for some error messages that
use PanicAlert. We want the user to actually understand why the error
occurred.
- remove unused variables
- reduce the scope where it makes sense
- correct limits (did you know that strcat()'s last parameter does not
include the \0 that is always added?)
- set some free()'d pointers to NULL