Fix Syntax Error in Besieged.lua

There was an error in closing the assault function after the merging of the instancing branch. This made the file fail to compile, which broke other stuff.
Merge pull request #272 from starlightknight/beseiged-lua-syntax-fix

Fix Syntax Error in Besieged.lua
SQL: add mission instances, salvage to instance_list.sql
Merge branch 'master' of https://github.com/DarkstarProject/darkstar
SQL: rename bcnm_instance.sql