Core - Added ColorGradient type to use for.. gradients!

Core - Initialisation process no longer takes place in core constructor and is no longer async
UI - Fixed exceptions during init not being shown
Gradient editor - Started work on this

src/Artemis.UI.Shared/Artemis.UI.Shared.csproj

@@ -43,6 +43,16 @@
   <ItemGroup>
     <None Remove="Resources\Fonts\RobotoMono-Regular.ttf" />
   </ItemGroup>
+  <ItemGroup>
+    <ProjectReference Include="..\Artemis.Core\Artemis.Core.csproj">
+      <Private>false</Private>
+    </ProjectReference>
+  </ItemGroup>
+  <ItemGroup>
+    <Reference Include="MaterialDesignExtensions">
+      <HintPath>..\..\..\..\.nuget\materialdesignextensions\3.0.0\lib\netcoreapp3.0\MaterialDesignExtensions.dll</HintPath>
+    </Reference>
+  </ItemGroup>
   <ItemGroup>
     <Resource Include="Resources\Fonts\RobotoMono-Regular.ttf" />
   </ItemGroup>