.NET: Fix build script - exclude optional jars, fix folder handling

diff --git a/modules/platforms/dotnet/build.ps1 b/modules/platforms/dotnet/build.ps1
index ecac051..d68ba5b 100644
--- a/modules/platforms/dotnet/build.ps1
+++ b/modules/platforms/dotnet/build.ps1
@@ -161,7 +161,8 @@
 
 Get-ChildItem $jarDirs.Split(',') *.jar -recurse `
    -include "ignite-core*","ignite-indexing*","ignite-shmem*","ignite-spring*","lucene*","h2*","cache-api*","commons-*","spring*" `
-   -exclude "*-sources*","*-javadoc*","*-tests*","*optional*" `
+   -exclude "*-sources*","*-javadoc*","*-tests*" `
+   | ? { $_.FullName -inotmatch '[\\/]optional[\\/]' } `
    | % { Copy-Item -Force $_ $libsDir }
    
 # Restore directory
@@ -247,9 +248,10 @@
         }
 
         if ($projName.StartsWith("Apache.Ignite")) {
-            $target = "$projName\bin\Release"
-            Make-Dir($target)
+            $target = [IO.Path]::Combine($projName, "bin", $configuration)
+            New-Item -Path $target -ItemType "directory" -Force
 
+            echo "Copying '$_' to '$target'"
             Copy-Item -Force $_.FullName $target
         }
     }