org-agenda.el: Rewrite of the redo/change/append commands

org-agenda.el: Rewrite of the redo/change/append commands

* org-agenda.el (org-agenda-local-vars): Remove
̀org-agenda-last-arguments' from the list of local variables.
(org-agenda-mode-map): `g' does the same than `r' in buffers
with only one agenda view, but its behavior differs when there
are several views.  In manually appended agendas (with `A'),
`g' displays only the agenda under the point.  With multiple
agenda blocks, `g' reinitializes the view by discarding any
temporary changes (e.g. with ̀f' or `w'), while ̀r' keeps those
temporary changes for the agenda view under the point.
(org-agenda-run-series, org-agenda-redo): Implement the above
changes.
(org-agenda-mark-header-line): Don't set useless properties.
(org-agenda-list, org-todo-only, org-search-view)
(org-todo-list, org-tags-view, org-agenda-list-stuck-projects)
(org-agenda-manipulate-query, org-agenda-goto-today)
(org-agenda-later, org-agenda-change-time-span): Use text
properties for storing the last command and the last arguments
for each agenda block.
(org-unhighlight-once): Delete.