Add basic ReHLDS and ReGameDLL support (#417)

* Add ReHLDS API files and its dependencies

Note: This has been stolen from ReAPI AMXX module and modified/adjusted to match AMXX existing includes and to provide as less dependencies as possible as well

* Add the necessary files to get ReHLDS interface

* Split SV_DropClient into pre/post code

* Init ReHLDS API and add SV_DropClient hook

* Add Cvar_DirectSet hook and adjust code with helpers

Note: we don't need to split code here. This is pretty much the naive and straight way, but fairly enough for our case. If it happens we got a lot more hooks, we may consider to use some class to manage better the things.

* Move platform and interface stuff in their own files in public directory

* Make sure to init cvar stuff after ReHLDS

* Add ReGameDLL API files and its dependencies in cstrike module

* Init ReHLDS in cstrike module and adjust code

Note: About cs_uset_set_model(). ReHLDS API doesn't offer a way to know directly the precached models, so instead of looping through all the ressources, the models list is saved one time at map change into a hashmap.

* Init ReGameDLL and adjust code

* Fix linux compilation

* Init ReGameDLL in fakemeta module and adjust code

* Rename /reapi directory to /resdk to avoid confusion

* Retrieve gamerules pointer through InstallGameRules in fakemeta module

* Retrieve gamerules pointer through InstallGameRules in cstrike module

Note: actually gamerules is not used if regamedll is enabled, but it could be used in future natives.

* Fix a typo when ReGameDLL is not enabled

* Fix missing interface check for ReHLDS.

I'm pretty sure I was checking at the very first since I worked first on vanilla version of engine, looks like change has been lost.

amxmodx/msvc12/amxmodx_mm.sln

@@ -1,7 +1,7 @@
 
 Microsoft Visual Studio Solution File, Format Version 12.00
-# Visual Studio 2013
-VisualStudioVersion = 12.0.31101.0
+# Visual Studio 14
+VisualStudioVersion = 14.0.25420.1
 MinimumVisualStudioVersion = 10.0.40219.1
 Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "amxmodx_mm", "amxmodx_mm.vcxproj", "{2BF64D1A-AC89-41B0-9D02-FB8CB610F850}"
 EndProject

amxmodx/msvc12/amxmodx_mm.vcxproj

@@ -151,6 +151,7 @@
     <ClCompile Include="..\..\public\memtools\CDetour\asm\asm.c" />
     <ClCompile Include="..\..\public\memtools\CDetour\detours.cpp" />
     <ClCompile Include="..\..\public\memtools\MemoryUtils.cpp" />
+    <ClCompile Include="..\..\public\resdk\mod_rehlds_api.cpp" />
     <ClCompile Include="..\..\third_party\hashing\hashers\crc32.cpp">
       <ObjectFileName Condition="'$(Configuration)|$(Platform)'=='JITDebug|Win32'">$(IntDir)hashing\</ObjectFileName>
       <ObjectFileName Condition="'$(Configuration)|$(Platform)'=='JITRelease|Win32'">$(IntDir)hashing\</ObjectFileName>
@@ -311,6 +312,10 @@
     <ClInclude Include="..\..\public\memtools\CDetour\detourhelpers.h" />
     <ClInclude Include="..\..\public\memtools\CDetour\detours.h" />
     <ClInclude Include="..\..\public\memtools\MemoryUtils.h" />
+    <ClInclude Include="..\..\public\resdk\common\hookchains.h" />
+    <ClInclude Include="..\..\public\resdk\engine\rehlds_api.h" />
+    <ClInclude Include="..\..\public\resdk\engine\rehlds_interfaces.h" />
+    <ClInclude Include="..\..\public\resdk\mod_rehlds_api.h" />
     <ClInclude Include="..\..\third_party\hashing\hashers\crc32.h" />
     <ClInclude Include="..\..\third_party\hashing\hashers\keccak.h" />
     <ClInclude Include="..\..\third_party\hashing\hashers\md5.h" />

amxmodx/msvc12/amxmodx_mm.vcxproj.filters

@@ -46,6 +46,15 @@
     <Filter Include="Third Party\Hashing\hashers">
       <UniqueIdentifier>{fb5fd616-bb2e-42f1-a113-a61eb9ead739}</UniqueIdentifier>
     </Filter>
+    <Filter Include="ReSDK">
+      <UniqueIdentifier>{5dd87e1c-9be5-43d3-8216-74d36f4f7610}</UniqueIdentifier>
+    </Filter>
+    <Filter Include="ReSDK\common">
+      <UniqueIdentifier>{26cdecf1-06de-459e-9ea0-0bbb4a2b3bf6}</UniqueIdentifier>
+    </Filter>
+    <Filter Include="ReSDK\engine">
+      <UniqueIdentifier>{04fab577-6f56-40d0-8f69-7ce1b8bf3bb9}</UniqueIdentifier>
+    </Filter>
   </ItemGroup>
   <ItemGroup>
     <ClCompile Include="..\amx.cpp">
@@ -291,6 +300,9 @@
     <ClCompile Include="..\CoreConfig.cpp">
       <Filter>Source Files</Filter>
     </ClCompile>
+    <ClCompile Include="..\..\public\resdk\mod_rehlds_api.cpp">
+      <Filter>ReSDK</Filter>
+    </ClCompile>
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="..\amx.h">
@@ -503,6 +515,18 @@
     <ClInclude Include="..\CFrameAction.h">
       <Filter>Header Files</Filter>
     </ClInclude>
+    <ClInclude Include="..\..\public\resdk\common\hookchains.h">
+      <Filter>ReSDK\common</Filter>
+    </ClInclude>
+    <ClInclude Include="..\..\public\resdk\engine\rehlds_api.h">
+      <Filter>ReSDK\engine</Filter>
+    </ClInclude>
+    <ClInclude Include="..\..\public\resdk\engine\rehlds_interfaces.h">
+      <Filter>ReSDK\engine</Filter>
+    </ClInclude>
+    <ClInclude Include="..\..\public\resdk\mod_rehlds_api.h">
+      <Filter>ReSDK</Filter>
+    </ClInclude>
   </ItemGroup>
   <ItemGroup>
     <ResourceCompile Include="..\version.rc">