Issue #2228087 by quietone, longwave, Kristen Pol, jungle, VladimirAus, phayes: PhpStreamWrapperInterface lacks docblocks

Issue #1314214 by stefan.r, phayes, ergophobe, YesCT, damienwhaley, kbasarab, Tor Arne Thune, basic, pfrenssen, yannickoo, simolokid, fietserwin, bzrudi71: MySQL driver does not support full UTF-8 (emojis, asian symbols, mathematical symbols)

Revert "Issue #1314214 by stefan.r, phayes, ergophobe, YesCT, damienwhaley, Tor Arne Thune, kbasarab, pfrenssen, basic, yannickoo, simolokid: MySQL driver does not support full UTF-8 (emojis, asian symbols, mathematical symbols)"

This reverts commit b105158a.

Issue #1314214 by stefan.r, phayes, ergophobe, YesCT, damienwhaley, Tor Arne Thune, kbasarab, pfrenssen, basic, yannickoo, simolokid: MySQL driver does not support full UTF-8 (emojis, asian symbols, mathematical symbols)

Issue #1668644 by Island Usurper, phayes, daffie, Brandonian, gease: PostgreSQL: Impossible to change a field to serial, bigserial, or numeric