Make import look in more places for packs

Now supports Curse/Twitch instance names
and folders containing minecraftinstance.json or manifest.json

curseforge/cursedir_windows.go

@@ -0,0 +1,25 @@
+package curseforge
+
+import (
+	"errors"
+	"os"
+	"path/filepath"
+
+	"golang.org/x/sys/windows"
+)
+
+func getCurseDir() (string, error) {
+	path, err := windows.KnownFolderPath(windows.FOLDERID_Documents, 0)
+	if err != nil {
+		return "", err
+	}
+	curseDir := filepath.Join(path, "Curse")
+	if _, err := os.Stat(curseDir); err == nil {
+		return curseDir, nil
+	}
+	curseDir = filepath.Join(path, "Twitch")
+	if _, err := os.Stat(curseDir); err == nil {
+		return curseDir, nil
+	}
+	return "", errors.New("Curse installation directory cannot be found")
+}