Build: Fixed some warnings about freeing static memory.
Standards.ASN1.Decode.simple_der_decode requires combined tag ids in "types".
Elaborate error message about NULs in the string.
Fundamental properties of empty strings corrected.

An empty string:
- is NOT lowercase.
- is NOT uppercase.
- does NOT have a minimum and maximum equal to zero.
Fix formatcheck to accomodate for the optional 2nd argument.