show the word list
a string. If missing do nothing, otherwise match against string to generate word list. Popup menu depending on length
add_bindings()
Add bindings to the entry box
clear_error()
Clear error message
clear_init_txt(...)
clear out init text, set back to black
find_match(x)
Find match in word list
make_styles(bg = "#ff6622")
Create tcl styles, cf http://paste.tclers.tk/506
set_error(msg)
Add error state and message to widget
set_init_txt(msg)
set initial text, gray out
set_invalid(value, msg)
Set widget as invalid or not
set_validator(FUN)
Set a function to do the validation
validate_input()
Return logical indicating if input is valid