5.6.3 for macOS

Following database backend is distributed with this version:

1. SQLite (distributed with Qt): Built in the package using command -plugin-sql-sqlite.

All builds have -no-openssl -securetransport, which means that Secure Transport library provided by macOS is used for TLS Backend.
This backend is supported by Qt since Qt 5.6.

All builds have -no-icu because I think the ICU library is too big and, in most of the conditions, useless for common users.

This build is done using an old compiler on an old macOS, and is unknown whether it can be run on newer systems.