Integrated "snipplets" code from @FObermaier in NetTopologySuite#77:

Two errors:
1. StableSort stuff not provided
2. I'm unable to reference "replacements" code only for NTS project when built for .NET 2.0

Author: Diego Guidi

.gitmodules

@@ -1,3 +0,0 @@
-[submodule "PowerCollections"]
-	path = PowerCollections
-	url = https://github.com/NetTopologySuite/PowerCollections

NetTopologySuite.IO/NetTopologySuite.IO.GeoTools/NetTopologySuite.IO.GeoTools.csproj

@@ -96,10 +96,6 @@
       <Project>{5770DAA9-84E5-4770-AF43-F6B815894368}</Project>
       <Name>NetTopologySuite</Name>
     </ProjectReference>
-    <ProjectReference Condition=" '$(NeedsPowerCollections)' != 'False' " Include="..\..\PowerCollections\Source\PowerCollections\PowerCollections.csproj">
-      <Project>{5821977d-ac2c-4912-bcd0-6e6b1a756167}</Project>
-      <Name>PowerCollections</Name>
-    </ProjectReference>
     <ProjectReference Include="..\NetTopologySuite.IO.ShapeFile\NetTopologySuite.IO.ShapeFile.csproj">
       <Project>{ab9096a7-89dd-4abd-b535-a5258863f389}</Project>
       <Name>NetTopologySuite.IO.ShapeFile</Name>
@@ -127,4 +123,4 @@
   <Target Name="AfterBuild">
   </Target>
   -->
-</Project>
+</Project>