GH-1389 wrap QDesktopServices and QProcess::startDetached

Essentially do not pass some environment variables to subprocesses:
* LD_PRELOAD
* LD_LIBRARY_PATH
* LD_DEBUG
* QT_PLUGIN_PATH
* QT_FONTPATH

logic/FileSystem.cpp

@@ -6,8 +6,8 @@
 #include <QSaveFile>
 #include <QFileInfo>
 #include <QDebug>
-#include <QDesktopServices>
 #include <QUrl>
+#include <QStandardPaths>
 
 namespace FS {
 
@@ -304,22 +304,6 @@ QString DirNameFromString(QString string, QString inDir)
 	return dirName;
 }
 
-void openDirInDefaultProgram(QString path, bool ensureExists)
-{
-	QDir parentPath;
-	QDir dir(path);
-	if (!dir.exists())
-	{
-		parentPath.mkpath(dir.absolutePath());
-	}
-	QDesktopServices::openUrl(QUrl::fromLocalFile(dir.absolutePath()));
-}
-
-void openFileInDefaultProgram(QString filename)
-{
-	QDesktopServices::openUrl(QUrl::fromLocalFile(filename));
-}
-
 // Does the directory path contain any '!'? If yes, return true, otherwise false.
 // (This is a problem for Java)
 bool checkProblemticPathJava(QDir folder)
@@ -449,4 +433,4 @@ bool createShortCut(QString location, QString dest, QStringList args, QString na
 	return false;
 #endif
 }
-}
+}