New sorting and marking commands, and fix insert-item function

simple-call-tree-insert-item: make sure marks are inserted when relisting items.
New sorting command: simple-call-tree-sort-by-mark
New marking command: simple-call-tree-mark-tag-match
New option: simple-call-tree-org-not-done-keywords

Altered items:
simple-call-tree-default-sort-method,
simple-call-tree-org-not-done-keywords, simple-call-tree-mode,
simple-call-tree-list-callees-recursively,
simple-call-tree-insert-item, simple-call-tree-insert-org-header,
simple-call-tree-sort, simple-call-tree-sort-by-mark,
simple-call-tree-store-state, simple-call-tree-marked-p,
simple-call-tree-mark-by-pred, simple-call-tree-toggle-marks,
simple-call-tree-mark-by-name, simple-call-tree-mark-by-source,
simple-call-tree-mark-tag, simple-call-tree-mark-tag-match
Bugfix: simple-call-tree-set-attribute + more mark commands

Altered items:
simple-call-tree-org-not-done-keywords,
simple-call-tree-org-priority-levels, simple-call-tree-set-attribute,
simple-call-tree-set-todo, simple-call-tree-set-priority,
simple-call-tree-apply-to-marked, simple-call-tree-set-todo-marked,
simple-call-tree-add-tag-marked, simple-call-tree-set-priority-marked,
simple-call-tree-remove-tag-marked, simple-call-tree-add-tags-marked,
simple-call-tree-set-tags-marked, not
Change operation commands to work on marked items

Also change simple-call-tree-get-item to a function.

Altered items:
simple-call-tree-get-item, simple-call-tree-mode,
simple-call-tree-invert, simple-call-tree-set-attribute,
simple-call-tree-set-todo, simple-call-tree-next-todo,
simple-call-tree-prev-todo, simple-call-tree-set-priority,
simple-call-tree-up-priority, simple-call-tree-down-priority,
simple-call-tree-set-tags, simple-call-tree-add-tags,
simple-call-tree-current-function, simple-call-tree-export-org-tree,
simple-call-tree-export-items, simple-call-tree-narrow-to-function,
simple-call-tree-apply-command, simple-call-tree-query-replace,
simple-call-tree-query-replace-regexp, simple-call-tree-eval-defun,
simple-call-tree-bookmark, simple-call-tree-mark-by-tag-match,
simple-call-tree-apply-to-marked, simple-call-tree-set-todo-marked,
simple-call-tree-set-priority-marked,
simple-call-tree-mark-by-priority, simple-call-tree-add-tags-marked,
simple-call-tree-mark-by-todo, simple-call-tree-set-tags-marked,
simple-call-tree-mark-by-face, simple-call-tree-hide-marked,
simple-call-tree-unhide