pttkview - tk GUI encrypted file viewer

[clach04]

From #1

[clach04]

Initial viewer (only) implemented. Needs polishing (along with edit/save support).
tkinter resources to checkout:

• https://docs.python.org/3/library/tkinter.scrolledtext.html
• https://dafarry.github.io/tkinterbook/text.htm
• https://www.tcl.tk/man/tcl8.5/TkCmd/text.html#M65
• https://github.com/pybee/tkreadonly
• https://docs.python.org/3/library/tk.html?highlight=tk
• https://docs.python.org/3/faq/gui.html?highlight=tk
• https://docs.python.org/3/library/tkinter.ttk.html?highlight=tk
• https://docs.python.org/3/library/tkinter.html?highlight=tk#tkinter.Tk
• https://docs.python.org/3/library/tkinter.html?highlight=tk#module-tkinter
• https://docs.python.org/3/library/tkinter.dnd.html?highlight=tk#module-tkinter.dnd
• https://docs.python.org/3/library/dialog.html?highlight=tk#module-tkinter.filedialog
• https://docs.python.org/3/library/dialog.html?highlight=tk#module-tkinter.simpledialog
• https://docs.python.org/3/library/tkinter.messagebox.html?highlight=tk#module-tkinter.messagebox

[clach04]

Todo

• ✔️ Test write with errors; divide by zero and Unicode character outside of codec. Display message rather then loose text. 92c362d
• ✔️remove debug print calls - 735ce85
• ✔️handle \r under Windows - I believe this is complete 4e82bab