Support a maximum building range (Fixes #2156).

This also implements support for a per-provider
cooldown between placing structures, allowing mods
with multiple structure queues to rate-limit
placement around a single provider.

An initial delay parameter is included to
support units that deploy into a base provider and
require an initial setup time (e.g. the Surveyor
unit from C&C TW).

The range and time restrictions are not applied to
walls as a balance choice.

OpenRA.Mods.RA/OpenRA.Mods.RA.csproj

@@ -422,6 +422,7 @@
     <Compile Include="Infiltrates.cs" />
     <Compile Include="Armament.cs" />
     <Compile Include="DebugMuzzlePositions.cs" />
+    <Compile Include="Buildings\BaseProvider.cs" />
   </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="..\OpenRA.FileFormats\OpenRA.FileFormats.csproj">