Fix/extension deletion (#160)

- fixed the deletion of extensions when there are several of them in the same directory
- fixed the deletion of hidden files on windows

daemon/extension/ExtensionManager.cpp

@@ -188,10 +188,24 @@ namespace ExtensionManager
 	{
 		const char* location = ext.GetLocation();
 
-		CString err;
-		if (FileSystem::DirectoryExists(location) && FileSystem::DeleteDirectoryWithContent(location, err))
+		ptrdiff_t count = std::count_if(
+			std::cbegin(m_extensions),
+			std::cend(m_extensions),
+			[&location](const auto& ext) { return strcmp(location, ext->GetLocation()) == 0; }
+		);
+
+		if (count > 1)
+		{
+			// for backward compatibility, when multiple V1 extensions placed 
+			// in the same directory in which case we have to delete an entry file, 
+			// not the entire directory.
+			location = ext.GetEntry();
+		}
+
+		if (FileSystem::DirectoryExists(location))
 		{
-			if (!err.Empty())
+			CString err;
+			if (!FileSystem::DeleteDirectoryWithContent(location, err))
 			{
 				return boost::optional<std::string>(err.Str());
 			}

daemon/util/FileSystem.cpp

@@ -520,6 +520,7 @@ bool FileSystem::CopyFile(const char* srcFilename, const char* dstFilename)
 bool FileSystem::DeleteFile(const char* filename)
 {
 #ifdef WIN32
+	SetFileAttributes(filename, FILE_ATTRIBUTE_NORMAL);
 	return _wremove(UtfPathToWidePath(filename)) == 0;
 #else
 	return remove(filename) == 0;