Fixed C++/CLI to handle namespace conflicts between free functions and namespaces.

We generate free functions inside a global namespace-level class with the same name as the header. This means that there might be some conflict if we already have a class with the same name as the header. This fix changes the code to always fully quality classes so the code always compiles correctly.

src/Generator/Generators/CLI/CLISourcesTemplate.cs

@@ -654,7 +654,7 @@ namespace CppSharp.Generators.CLI
             WriteLine("{0}^ {0}::{1}(::System::IntPtr native)", qualifiedIdentifier, Helpers.CreateInstanceIdentifier);
 
             WriteStartBraceIndent();
-            WriteLine("return gcnew {0}(({1}) native.ToPointer());", qualifiedIdentifier, nativeType);
+            WriteLine("return gcnew ::{0}(({1}) native.ToPointer());", qualifiedIdentifier, nativeType);
             WriteCloseBraceIndent();
             NewLine();
         }

tests/CLITemp/CLITemp.cpp

@@ -9,3 +9,8 @@ std::string Date::testStdString(std::string s)
 {
     return s + "_test";
 }
+
+void testFreeFunction()
+{
+
+}

tests/CLITemp/CLITemp.h

@@ -47,3 +47,5 @@ std::ostream& operator<<(std::ostream& os, const Date& dt)
     os << dt.mo << '/' << dt.da << '/' << dt.yr;
     return os;
 }
+
+DLL_API void testFreeFunction();