Teach erl-search-function to ignore arity when failed

to handle the case when the input is incomplete. Also use regexp
search since there might be space between the function NAME and (. See
the yaws source for examples.

Two trivial renames:
 - rename process-list-mode to erl-process-list-mode.
 - rename erl-cookie derl-cookie.
Hide edb internal functions and prefix break point accessors
Rename check-event to fsm-check-event for clarity

since 'event' is a native concept of emacs.
Merge pull request #29 from leoliu/master

Teach erl-search-function to ignore arity when failed