Factor .NET framework build version setup code to fix a bug for dependent projects.

build/Helpers.lua

@@ -72,6 +72,21 @@ function SetupManagedProject()
       location "."
     configuration(c)
   end
+
+  if action == "vs2015" then
+
+  configuration "vs2015"
+    framework "4.6"
+
+  end
+
+  configuration "vs2013"
+    framework "4.5"
+
+  configuration "vs2012"
+    framework "4.5"
+
+  configuration {}
 end
 
 function IncludeDir(dir)

build/premake5.lua

@@ -22,19 +22,6 @@ solution "CppSharp"
   targetdir (libdir)
   debugdir (bindir)
 
-  if action == "vs2015" then
-
-  configuration "vs2015"
-    framework "4.6"
-
-  end
-
-  configuration "vs2013"
-    framework "4.5"
-
-  configuration "vs2012"
-    framework "4.5"
-
   configuration "windows"
     defines { "WINDOWS" }