tools: use dotnet build in VS2015 CI

tools/gensrc/remove-sln-project.ps1

@@ -0,0 +1,12 @@
+param (
+    [Parameter(Mandatory)][string]$Path,
+    [Parameter(Mandatory)][string]$Match
+)
+
+echo "Removing projects that match $($Match) from $($Path)"
+
+Get-Content $Path -Delimiter 'EndProject' |
+  Where-Object {$_ -notlike $Match} |
+  Set-Content "$($Path).new"
+  
+ Move-Item -Path "$($Path).new" -Destination $Path -Force