BAGHDAD (Reuters) - Iraqis reacted with anger and disbelief Wednesday to news that British-Iraqi aid worker Margaret Hassan, who worked in Iraq (news - web sites) for decades before being kidnapped a month ago, had been killed by her captors. Irish-born Hassan, 59, moved to Iraq more than 30 years ago after marrying an Iraqi engineer. She learned Arabic and became a pillar of support in local communities, often helping the needy in the face of opposition during Saddam Hussein (news - web sites)'s regime. Those who knew her, worked with her or were helped by her described Hassan as...