(tex-define-common-keys): Remove key binding of tex-feed-input.

(tex-define-common-keys): Remove key binding of tex-feed-input.
(tex-mode-map): Bind tex-feed-input here.
(tex-start-shell): Use compilation-shell-minor-mode.  Set
comint-input-filter-functions before running tex-shell-hook.
(tex-start-tex): Forget compilation errors.
(tex-compilation-parse-errors): Rewritten to work also with
compile-mouse-goto-error and compile-goto-error.  Adjusted to
change in tex-region.
(tex-region): For the temp file use file-name without directory.
(tex-file): Expand file name of tex-print-file.