* Add cassert and debug/gdb flags for test image builder.

* all the fixes for bad varhdrz usage, and switch all _P to _PP macros

* fix oversized base64 decoding bug.

* Add vscode include path

When the getkey_script file is missing, previous startup error
message was wrongly showing "Permission denied for %s". This shows
a relevant error message with addition of some details and hints.

The patch also improves other startup error/log messages
so they repect the PostgreSQL log format if stderr is collected.

A key is valid at far as its expires date is greater than current
date and time.

Fixes #41

* aead ietf check null inputs.

* test for NULL on aead_ietf, allow NULL associated data with aead_det

* also NULL associated data with aead_ietf

* NULL check inputs on auth functions.

* null checks for box, derive, hash, and helpers

* null input checks for hmac.

* null input checks for kdf.

* NULL argument checking on the rest of the library.

* fix missing newline

* fix whitespace

* thanks for -x my test script github!

* bump version.

* bump version