more crlf

crlf -> lf

merge from ileo-exp. Now requires trunk version of leo

jobctrl.py: added %jobqueue for queueued system jobs

%tasks clear: clear task list

%cd: do not add same dir to dhist twice in a row

add pre_prompt_hook; run just before displaying the prompt (safe place to display stuff asynchronously without messing up text entry)

ipy_leo: do not crash if _p has been deleted in push

ipy_leo: implement support for @ipy-root

merge