Issue #2966523 by alexpott, blakemorgan, almaudoh, gapple, Mixologic, amateescu, bojanz: MySQL 8 Support

(cherry picked from commit 3c106b9f789eb3734f4b65db12dae34754322c82)

Issue #2665992 by alexpott, klausi, heykarthikwithu, xjm, tstoeckler: @file is not required for classes, interfaces and traits

Issue #2594845 by er.manojsharma, tarekdj, snehi, dpopdan, anil280988, jhodgdon, cilefen: Many database driver classes have no class doc blocks