Minor documentation changes. No code updates.

Fix how floating points are converted into integers to avoid undefined behaviour. Prior to this, floating points were simply cast; however, this would introduce UB if the floating point over or underflowed the integer. Check for saturating prior to casting now and also handle NaN checks. This adds SQLBOX_DOUBLE_MAX_INT and SQLBOX_DOUBLE_MIN_INT macros to the API. They may be used for more refined casting by the application, and are used in the regression tests to check for corner cases.

Introduce -fsanitize testing for address and undefined behaviour sanitisation in the CI. This bolsters the existing valgrind checks.

Automated testing using GitHub actions (regressions, valgrind, etc.). Installing dynamic library alongside static.

Continue refining portability in the build system.

Use pkg-config internally and also produce a configuration for it. This simplifies configuration (no need to invoke configure with additional arguments) and makes using the library easier.

This also removes OpenBSD needing -lpthread for -lsqlite3, which ended up being a problem on my development machine with an old version of the library hanging out in the default path.

Fix a copypasta where transactions are always rolled-back instead of being committed. Regression tests added for this behaviour.

Ported to FreeBSD. No changes otherwise.

Have the internal logging functions behave the same whether called in the parent or child process. This means that sqlbox_msg_set_dat(3) has its buffer copied in both processes.

Don't emit a warning message when calling sqlbox_free(3) with open databases. Only do this if the child exits without an explicit instruction.

Add a general sinks and sources (starts) to the hierarchical role generator. These are commonly-used idioms.

Also fix where passing zero (implicit addressing) as a statement or database identifier would use the first queue entry, not the last, breaking nested statements that use implicit addressing.

Add compilation instructions for OpenBSD 6.6, which requires -lpthread to be used for all applications or they will silently hang when the database is opened.

Add a set of functions for creating hierarchical roles. This simplifies the creation of complex systems inheriting roles.

Require that all databases are foreign key enabled.

Add conversion routines (e.g., sqlbox_parm_int(3)) between results. These are convenience routines and simply allow easier replacement of prior ksql deployments that take advantage of sqlite3's value conversions.

First public release. This already has about 130 regression tests for behaviour and has been heavily orchestrated with valgrind.