Add lint check for invalid projectile angles

Emits error if
- angle exceeds 255 or -255
- minimum launch angle exceeds maximum launch angle

OpenRA.Mods.Common/OpenRA.Mods.Common.csproj

@@ -168,6 +168,7 @@
     <Compile Include="HitShapes\Capsule.cs" />
     <Compile Include="HitShapes\Circle.cs" />
     <Compile Include="Lint\CheckBuildingFootprint.cs" />
+    <Compile Include="Lint\CheckAngle.cs" />
     <Compile Include="Lint\CheckSequences.cs" />
     <Compile Include="Lint\CheckPalettes.cs" />
     <Compile Include="Lint\CheckPlayers.cs" />