Use a mode-line spec rather than a static string in Semantic.

Use a mode-line spec rather than a static string in Semantic.
* cedet/semantic/util-modes.el:
(semantic-minor-modes-format): New var to replace...
(semantic-minor-modes-status): Remove.
(semantic-mode-line-update): Construct a mode-line spec rather than
a static string so that mouse buttons can be used on individual minor
modes and so that semantic-mode-line-update only needs to be called
when global settings are changed.
(semantic-add-minor-mode, semantic-toggle-minor-mode-globally):
Call semantic-mode-line-update.
(semantic-toggle-minor-mode-globally): Don't assume mode is on
minor-mode-alist, check semantic-minor-mode-alist as well.
(semantic-stickyfunc-mode, semantic-show-parser-state-auto-marker)
(semantic-show-parser-state-marker, semantic-show-parser-state-mode)
(semantic-show-unmatched-syntax-mode, semantic-highlight-edits-mode):
* cedet/semantic/mru-bookmark.el (semantic-mru-bookmark-mode):
* cedet/semantic/idle.el (semantic-idle-scheduler-mode)
(define-semantic-idle-service, semantic-idle-summary-mode):
* cedet/semantic/decorate/mode.el (semantic-decoration-mode):
Don't call semantic-mode-line-update any more.