Change moving to prev/next word - regard consecutive word-split characters as a single word

[svekko]

At the moment each word-split character is being regarded as a separate word in move_to_next_word and move_to_prev_word, but not in remove_until_word_start. Changed the behavior in move_to_next_word and move_to_prev_word so that each word-split character mustn't be cycled through one-by-one, but rather consider consecutive word-split characters as a part of the previous word.

[nuta]

Looks good. Thanks for the fix!