Detection of fancy-pants steam installs about ckan

[HebaruSan]

I think this was completed in #146. The current code looks up a Steam registry key on Windows here:

CKAN/Core/CKANPathUtils.cs

Lines 42 to 50 in 62a0bc7

	private const string steamRegKey = @"HKEY_CURRENT_USER\Software\Valve\Steam";
	private const string steamRegValue = @"SteamPath";
	private static string[] SteamPaths
	=> Platform.IsWindows ? new string[]
	{
	// First check the registry
	(string)Microsoft.Win32.Registry.GetValue(steamRegKey, steamRegValue, null),
	}

This is used to find Steam's config/config.vdf, which lists the Steam library locations, each of which is checked for a SteamApps/common/Kerbal Space Program folder:

CKAN/Core/Games/KerbalSpaceProgram.cs

Lines 49 to 73 in 62a0bc7

	// Attempt to find through config file
	string configPath = Path.Combine(steamPath, "config", "config.vdf");
	if (File.Exists(configPath))
	{
	log.InfoFormat("Found Steam config file at {0}", configPath);
	StreamReader reader = new StreamReader(configPath);
	string line;
	while ((line = reader.ReadLine()) != null)
	{
	// Found Steam library
	if (line.Contains("BaseInstallFolder"))
	{
	// This assumes config file is valid, we just skip it if it looks funny.
	string[] split_line = line.Split('"');
	if (split_line.Length > 3)
	{
	log.DebugFormat("Found a Steam Libary Location at {0}", split_line[3]);
	installPath = KSPDirectory(split_line[3]);
	if (installPath != null)
	{
	log.InfoFormat("Found a KSP install at {0}", installPath);
	return installPath;
	}

CKAN/Core/Games/KerbalSpaceProgram.cs

Lines 337 to 342 in 62a0bc7

	string installPath = Path.Combine(steamPath, "SteamApps", "common", "Kerbal Space Program");
	if (Directory.Exists(installPath))
	{
	return installPath;
	}

That seems to satisfy the intent of this issue. If more is needed, we'd have to know what was missing in more detail. (And I don't remember ever seeing a user report that CKAN failed to detect a Steam install.)