move xmlgame to client.common and refactor it a bit in order to achieve that

BizHawk.Client.Common/BizHawk.Client.Common.csproj

@@ -33,6 +33,9 @@
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
   </PropertyGroup>
   <ItemGroup>
+    <Reference Include="ICSharpCode.SharpZipLib">
+      <HintPath>..\ICSharpCode.SharpZipLib.dll</HintPath>
+    </Reference>
     <Reference Include="Newtonsoft.Json">
       <HintPath>..\Newtonsoft.Json.dll</HintPath>
     </Reference>
@@ -112,6 +115,7 @@
     <Compile Include="tools\RamSearchEngine.cs" />
     <Compile Include="tools\Watch.cs" />
     <Compile Include="tools\WatchList.cs" />
+    <Compile Include="XmlGame.cs" />
   </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="..\BizHawk.Common\BizHawk.Common.csproj">

BizHawk.Client.Common/XmlGame.cs

@@ -5,9 +5,7 @@ using System.Text;
 using System.IO;
 using System.Xml;
 
-using BizHawk.Client.Common;
-
-namespace BizHawk.MultiClient
+namespace BizHawk.Client.Common
 {
 	public class XmlGame
 	{
@@ -96,10 +94,9 @@ namespace BizHawk.MultiClient
 				}
 				return ret;
 			}
-			catch (Exception e)
+			catch(Exception ex)
 			{
-				System.Windows.Forms.MessageBox.Show(e.ToString(), "XMLGame Load Error");
-				return null;
+				throw new InvalidOperationException(ex.ToString());
 			}
 		}
 

BizHawk.MultiClient/BizHawk.MultiClient.csproj

@@ -737,7 +737,6 @@
     <Compile Include="tools\Watch\WatchValueBox.cs">
       <SubType>Component</SubType>
     </Compile>
-    <Compile Include="XmlGame.cs" />
     <EmbeddedResource Include="AVOut\FFmpegWriterForm.resx">
       <DependentUpon>FFmpegWriterForm.cs</DependentUpon>
     </EmbeddedResource>

BizHawk.MultiClient/MainForm.cs

@@ -1228,10 +1228,9 @@ namespace BizHawk.MultiClient
 					}
 					else if (file.Extension.ToLower() == ".xml")
 					{
-						var XMLG = XmlGame.Create(file);
-
-						if (XMLG != null)
+						try
 						{
+							var XMLG = XmlGame.Create(file); // if load fails, are we supposed to retry as a bsnes XML????????
 							game = XMLG.GI;
 
 							switch (game.System)
@@ -1256,9 +1255,11 @@ namespace BizHawk.MultiClient
 								default:
 									return false;
 							}
-
 						}
-						// if load fails, are we supposed to retry as a bsnes XML????????
+						catch(Exception ex)
+						{
+							System.Windows.Forms.MessageBox.Show(ex.ToString(), "XMLGame Load Error");
+						}
 					}
 					else // most extensions
 					{