Turing β-0.9

Fixed

• Fix thread lock (#37) [5b863dc]
• Refactor main.py code [b788231]
• Put global variables in state objects [eb51827]
• Fix "grad" parameters of graph window [f945cae]
• New and Open buttons are disabled when program is running [9910729]
• Fix old Linux distros build [18a204e]
• Fix macOS execution and release packaging [8b2684f]
• Fix line number in error messages [5eec755]
• Fix auto step in FOR-loops [c3c18ba]
• Fix range and irange wrappers [9192ee4]
• Embed editor backend in main binary [6ef59ea]

Added

• Add new French arrow notation (#43) [1fc1ce7]
• Add shitty Candy theme [86c9b5e]
• Add important program feature enhancement [2b1bde4]
• Add inverse Erf and Erfc [49b0c1d]
• Normal distribution functions [f87c36d]