[m12533] Added unique summon action to EventAI.

ACTION_T_SUMMON_UNIQUE allows creatures to only summon if the summoned
creature has not yet been summoned.

Signed-off-by: Daniel S. Reichenbach <daniel@kogitoapp.com>
Fixed a NULL pointer dereference.

Signed-off-by: Daniel S. Reichenbach <daniel@kogitoapp.com>
Updated the list of ignored files and directories.

Files generated during builds should no longer show up as modified,
added, etc.

Signed-off-by: Daniel S. Reichenbach <daniel@kogitoapp.com>
Added ChangeLog template.

Signed-off-by: Daniel S. Reichenbach <daniel@kogitoapp.com>
[m12534] SPELL_ATTR_UNK7 changed to SPELL_ATTR_HIDE_SPELL.

Spells with SPELL_ATTR_HIDE_SPELL set, will be hidden in the game
client. This usually concerns buffs for creature stats.

Signed-off-by: Daniel S. Reichenbach <daniel@kogitoapp.com>
[m12535] Renamed table scripted_event_id to scripted_event.

Signed-off-by: Daniel S. Reichenbach <daniel@kogitoapp.com>
Renamed SPELLFAMILY_UNK1 to SPELLFAMILY_ENVIRONMENT.

Spells in this category usually provide environmental changes.

Signed-off-by: Daniel S. Reichenbach <daniel@kogitoapp.com>
Remove a duplicate comment start.

Signed-off-by: Daniel S. Reichenbach <daniel@kogitoapp.com>
Updated change log for release 0.18.0

Signed-off-by: Daniel S. Reichenbach <daniel@kogitoapp.com>
Merge branch 'release/0.18.0'