Several improvements for Onyxia encounter

* Add support for Onyxia Eggs: Onyxian Whelp will now spawn from the
eggs when players enter the tunnels. Prepare for $@& Minus 50 DKP!!!
* Rework timer of Bellowing Roar
* Onyxia will yell when players try to lure her out of her lair. Dirty
cowards.
* Add support for the respawning of Onyxian Warders in the corridor
while fighting Onyxia to prevent players from hiding there from the whelps.
Tss, tss... cooowaaaards...
* Complete rework of Onyxian Whelps summoning in Phase 2. Now Blizzlike
in the gameplay, probably still not Blizzlike in the implementation

Sources:
- https://www.youtube.com/watch?v=BOKlXklfzzE
- http://www.youtube.com/watch?v=ziPQ8ukpuLA
- https://www.youtube.com/watch?v=vFAUEId4PQg

(based on 844460bc75)

sql/scriptdev2/scriptdev2.sql

@@ -2548,7 +2548,8 @@ INSERT INTO script_texts (entry,content_default,sound,type,language,emote,commen
 (-1249001,'Learn your place mortal!',0,1,0,0,'onyxia SAY_KILL'),
 (-1249002,'This meaningless exertion bores me. I\'ll incinerate you all from above!',0,1,0,254,'onyxia SAY_PHASE_2_TRANS'),
 (-1249003,'It seems you\'ll need another lesson, mortals!',0,1,0,293,'onyxia SAY_PHASE_3_TRANS'),
-(-1249004,'%s takes in a deep breath...',0,3,0,0,'onyxia EMOTE_BREATH');
+(-1249004,'%s takes in a deep breath...',0,3,0,0,'onyxia EMOTE_BREATH'),
+(-1249005,'You seek to lure me from my clutch? You shall pay for your insolence!',0,1,0,0,'onyxia SAY_KITE');
 
 -- -1 269 000 OPENING OF THE DARK PORTAL (BLACK MORASS)
 INSERT INTO script_texts (entry,content_default,sound,type,language,emote,comment) VALUES