destructible trees for both CnC and RA mod

- move DeadBuildingState to OpenRA.Mods.RA
- don't loop sequences with length > 1

OpenRA.Mods.Cnc/OpenRA.Mods.Cnc.csproj

@@ -1,4 +1,4 @@
-<?xml version="1.0" encoding="utf-8"?>
+<?xml version="1.0" encoding="utf-8"?>
 <Project ToolsVersion="4.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <PropertyGroup>
     <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
@@ -76,7 +76,6 @@
     <Compile Include="Activities\HarvesterDockSequence.cs" />
     <Compile Include="CncLoadScreen.cs" />
     <Compile Include="CncMenuPaletteEffect.cs" />
-    <Compile Include="DeadBuildingState.cs" />
     <Compile Include="Effects\IonCannon.cs" />
     <Compile Include="IonCannonPower.cs" />
     <Compile Include="Missions\CncShellmapScript.cs" />