GOG multi-file installers

[tkashkin]

Some GOG installers (mainly for Windows) come in multiple files.

[tkashkin]

Example: The Witcher 2

"installers": [
	{
		"id": "installer_windows_en",
		"name": "Ведьмак 2: Убийцы королей",
		"os": "windows",
		"language": "en",
		"language_full": "English",
		"version": null,
		"total_size": 19189989376,
		"files": [
			{
				"id": "en1installer14",
				"size": 1048576,
				"downlink": "http://api.gog.com/products/1207658930/downlink/installer/en1installer14"
			},
			{
				"id": "en1installer15",
				"size": 4194304000,
				"downlink": "http://api.gog.com/products/1207658930/downlink/installer/en1installer15"
			},
			{
				"id": "en1installer16",
				"size": 4194304000,
				"downlink": "http://api.gog.com/products/1207658930/downlink/installer/en1installer16"
			},
			{
				"id": "en1installer17",
				"size": 4194304000,
				"downlink": "http://api.gog.com/products/1207658930/downlink/installer/en1installer17"
			},
			{
				"id": "en1installer18",
				"size": 4194304000,
				"downlink": "http://api.gog.com/products/1207658930/downlink/installer/en1installer18"
			},
			{
				"id": "en1installer19",
				"size": 2411724800,
				"downlink": "http://api.gog.com/products/1207658930/downlink/installer/en1installer19"
			}
		]
	},
	{
		"id": "installer_mac_en",
		"name": "Ведьмак 2: Убийцы королей",
		"os": "mac",
		"language": "en",
		"language_full": "English",
		"version": "1.1 (gog-10)",
		"total_size": 20656947200,
		"files": [
			{
				"id": "en2installer2",
				"size": 20656947200,
				"downlink": "http://api.gog.com/products/1207658930/downlink/installer/en2installer2"
			}
		]
	},
	{
		"id": "installer_linux_en",
		"name": "Ведьмак 2: Убийцы королей",
		"os": "linux",
		"language": "en",
		"language_full": "English",
		"version": "Release 3 (20150306204412)",
		"total_size": 21185429504,
		"files": [
			{
				"id": "en3installer0",
				"size": 21185429504,
				"downlink": "http://api.gog.com/products/1207658930/downlink/installer/en3installer0"
			}
		]
	}
]