* lisp/vc/vc-git.el (vc-git-root-log-format): New option for
customizing log format.
(vc-git-print-log, vc-git-log-outgoing, vc-git-log-incoming)
(vc-git-log-view-mode): Use it.
(vc-git-expanded-log-entry): New function.
(vc-git-log-view-mode): Use it. Truncate lines in root log.
* lisp/vc/vc-hg.el (vc-hg-root-log-template): New option for
customizing log format.
(vc-hg-print-log): Use it.
(vc-hg-expanded-log-entry): New function.
(vc-hg-log-view-mode): Use vc-hg-root-log-template and
vc-hg-expanded-log-entry. Truncate lines in root log.
* lisp/vc/vc-bzr.el (vc-bzr-log-view-mode): Truncate lines in root log.
* lisp/vc/log-view.el (log-view-mode-menu): Add
log-view-toggle-entry-display.
* lisp/vc/log-view.el: New command log-view-toggle-entry-display for
toggling log entries between concise and detailed forms.
(log-view-toggle-entry-display): New command.
(log-view-mode-map): Bind RET to it.
(log-view-expanded-log-entry-function): New variable.
(log-view-current-entry, log-view-inside-comment-p)
(log-view-current-tag): New functions.
(log-view-toggle-mark-entry): Use log-view-current-entry and
log-view-end-of-defun instead of searching directly with
log-view-message-re.
(log-view-end-of-defun): Likewise. Add optional ARG for
compatibility with end-of-defun.
(log-view-end-of-defun): Ignore comments and VC buttons.
* lisp/vc/vc-bzr.el (vc-bzr-expanded-log-entry): New function.
(vc-bzr-log-view-mode): Use log-view-expanded-log-entry-function.
* lisp/vc/vc.el (vc-print-log-setup-buttons): Instead of using the
widget library for buttons, just use button.el.
* lisp/vc/log-view.el (log-view-mode-map): Don't inherit from
widget-keymap.