Address compiler warning

INTEGER to 64-bit native integer methods

aper: INTEGER longs to intmaxs

Copy operation

Class default syntax support

Update main README with supported encoding rules

jer: Remove implicit variables in ASN_DEBUGs

This reverts commit 818b21ba.

`NativeInteger_rfill.c` was sometimes ignoring the PER constrains. @lbm98 added a check which was also present in BIT_STRING_rfill.c to respect them.

.gitignore: Ignore generated smoke tests

aper: CHOICE cast different signedness comparison

jer: Remove unused arguments and variables

jer: Add missing 'fall through' marker comments

Should correctly address issue that #112 is trying to fix

Previous commit was wrong - va_end(args) is called once, and right where it belongs.

This is #401 from vlm/asn1c by @Inksz.

From his PR:
I do not know the project's code-style, in some C projects this kind of error-handling would incorporate a goto.
But because of the general avoidance of goto I added va_end before each return.

I suppose has more insight into what this function does, one could "dry" the error handling.