This adds licensing and copyright information where missing and normalises existing licensing/copyright statements to SPDX metadata tags.
Provide a custom base32 implementation; relates to issues: #9 and #6. In particular being able to control memory allocation prior to decoding base32 will help with resolving issue #6 in a (more) secure fashion.
This library is meant for private use by Keysmith, to simplify linking to the base32 functionality in CMake files.