(term-if-emacs19, term-if-xemacs, term-ifnot-xemacs): New macros
to conditionalize at compile-time for different emacs versions.
(various places): Use them (instead of term-is-XXXX).
(term-is-emacs19): Removed, no longer needed.
Change keybindings to not use C-c LETTER, for
term-char-mode, term-line-mode. Keybindings for term-pager-enable
and term-pager-disable replaced by one for term-pager-toggle.
(term-pager-toggle): New function.
(term-fake-pager-enable, term-fake-pager-disable):
Define as aliases, so that menubar code will find proper keybindings.
(term-char-mode): Make no-op if already in char mode.
(term-line-mode): Make no-op if already in line mode.
(term-mode-map): Add keybinding for no-op term-line-mode, so
code to display menubar keybindings doesn't lose it. (Needed
as long as char-mode and line-mode share term-terminal-menu.)
(term-raw-escape-map): Likewise for term-char-mode.
(term-char-mode, term-line-mode): Better documentation strings.
Added menubar for pager sub-mode.
(term-command-hook): Disabled the feature that allowed
inferior to send a lisp command to emacs - too big a security hole.
