Classic DB release version 1.9 "The Black Dragonflight"

This release is compatible with revision z2717 of of CMaNGOS-classic and
comes with latest ACID-classic

The main topic of this release are a rework of Blackwing Lair raid dungeon, a cleanup of Onyxia's Lair dungeon by Tobschinski and cala along with a rework of Zul'Gurub raid dungeon by Phatcat and oppahansi.

We would like to thank all the contributors for their reports, fixes and
tests, especially amongst them: bdedaere, Grz3s, killerwife, MantisLord, Muehe, RichardGe, Saltgurka...

As always, very special thanks to the other CMaNGOS teams as this release
would not have been possible without their great and heavy contributions.
Classic DB is a cross databases project and many of the updates are possible thanks to the great work of our fellow developers from other projects, with a special thank to Grz3s and killerwife who increased the synergies between our DB projects.

As usual, many gossips, quests, items, NPCs, events, dungeons and raids
were also fixed.