is_not_done_task function
get_next_lines() fucntion
jump_to_next_task() function
jump_line(lnum) function
fix bug about Jump_to_next_task()
get_previous_lines() function
Jump_to_previous_task() function with bug
add new lines
fix number
fix bug
add block surrounding functions
update readme and doc about jump_to_other_task() functions
update mapping for jump to other task function
update readme and doc file
up version
rename: not_done -> unfinished
delete todoenv prefix from local functions