* lisp/eshell/em-cmpl.el: Use completion-at-point i.s.o pcomplete
(eshell-cmpl-initialize): Refrain from binding to the `tab` key, which prevents the tab -> TAB remapping. Use completion-at-point and completion-help-at-point. (eshell-complete-commands-list): Use `fboundp` test instead of ugly gymnastics to try and hide the function call from the compiler. (eshell-pcomplete): Make it an alias of completion-at-point. * doc/misc/eshell.texi (Completion): Change wording to reflect different default behavior.