close #3, now we can select candidate in several step to create new words
and we have now the new word being created that is displayed below the preedit text
still need to clean the code though and implement correctly  left/right and backspace with this mode

removed preedit_display from the engine structure as it was only used inside one function

now we keep track of the consumed characters of
a step by step creation of word, and we put them back when pressing enter
if any

replaced action for 'delete key' event