Special menu

• General notes
• "Enter extra GSDs" menu item
• "Load extra GSDs" menu item
• "Save extra GSDs" menu item
• "Delete extra GSDs" menu item
• "Extra GSDs preferences (1)" menu item
• "Extra GSDs preferences (2)" menu item
• "Extra GSDs output table" menu item
• "Load GSDs as extra GSDs" menu item
• "Extra GSDs legend" menu item
• "Inner friction angle legend" menu item
• "Check grading curve range" menu item