org-agenda.el: Rewrite agenda filtering using text properties

* org-agenda.el (org-agenda-write): Code cleanup.
(org-agenda-mark-filtered-text)
(org-agenda-unmark-filtered-text)
(org-agenda-fix-tags-filter-overlays-at): Delete.
(org-agenda-remove-marked-text): Use the `property' argument
instead of hard-coding 'org-filtered.
(org-agenda-filter-remove-all): Use `org-agenda-finalize'.
(org-agenda-filter-hide-line): Rewrite using text properties
instead of overlays.
(org-agenda-remove-filter): New function.
(org-agenda-filter-show-all-tag)
(org-agenda-filter-show-all-cat)
(org-agenda-filter-show-all-re): Rewrite using
`org-agenda-remove-filter'.
Merge branch 'maint'
Make the point visible when jumping to the mark

* org.el: Advise commands which jump to the mark.
org.el (org-entry-properties): Ensure the special property is not commented out when matched

* org.el (org-entry-properties): Ensure the special property
is not commented out when matched.

Other an agenda view like (tags "DEADLINE<\"<+0d>\"" ...) will
wrongly list an entry with a commented out DEADLINE line, because
org-agenda-skip only skip commented out stuff on the current line,
with is the headline itself when using "tags" agenda.

Thanks to Sébastien for reporting this.
org-agenda.el (org-agenda-redo): Reapply the filters correctly

* org-agenda.el (org-agenda-redo): Reapply the filters
correctly.

TINYCHANGE
Merge branch 'maint'
lisp/ob-scheme.el: Fix scheme code blocks execution error in batch mode

* ob-scheme.el (org-babel-scheme-capture-current-message)
(org-babel-scheme-execute-with-geiser): Capture scheme code results
via `current-message' both in interactive mode and non interactive
mode.

`org-babel-scheme-execute-with-geiser' uses `current-message' to get
the results of scheme code blocks, but `current-message' always
returns nil in batch mode, and this patch fixes this.
org-agenda.el: Fixes for top headline filtering

* org-agenda.el (org-agenda-local-vars): Add
`org-agenda-top-headline-filter'.
(org-agenda-filter-by-category): Fix syntax.
(org-agenda-filter-show-all-top-filter): New function.
(org-agenda-filter-by-top-headline)
(org-agenda-filter-remove-all): Use the new function.
(org-agenda-filter-top-headline-apply): Use a dedicated symbol
`top-headline'.

Thanks to Greg Troxel who provided a preliminary patch.
Merge branch 'maint'
ox-ascii: Implement "justifyright" and "justifyleft" blocks

* lisp/ox-ascii.el
(org-ascii--justify-lines): New function.  Renamed from
`org-ascii--justify-string'.
(org-ascii--justify-element, org-ascii--current-justification): New
functions.
(org-ascii-verse-block, org-ascii-table-cell, org-ascii-table
  org-ascii-src-block, org-ascii-property-drawer, org-ascii-planning,
  org-ascii-paragraph, org-ascii-paragraph,
  org-ascii-latex-environment, org-ascii-keyword,
  org-ascii-horizontal-rule, org-ascii-fixed-width,
  org-ascii-export-block, org-ascii-example-block, org-ascii-clock,
  org-ascii-template--document-title,
  org-ascii-template--document-title): Use new functions.
(org-ascii-center-block): Do not process contents anymore since they
are already justified.

* doc/org.texi (ASCII/Latin-1/UTF-8 export): Document new feature.
  Also document `org-ascii-text-width' since this is closely related.

This patches also fixes centering of tables.
org-habit.el (org-habit-insert-consistency-graphs): Don't remove filter overlays

* org-habit.el (org-habit-insert-consistency-graphs): Don't
remove filter overlays as we don't use overlays for filters
anymore.
Merge branch 'maint'
org-agenda.el (org-cmp-ts): Fix call to `type'

* org-agenda.el (org-cmp-ts): Argument `type' is not optional.
Don't quote it.
Merge branch 'maint'
Merge branch 'master' into R-env
Splitting of loading into logical lists

* lisp/ob-R.el (org-babel-expand-body:R): splitting of commands for
  loading of R files into two logical lists (one for creation of
  environment, second for loading). These will be replaced by variables.
Make org:variables environment customizable

* lisp/ob-R.el
(org-babel-R-assign-elisp): Added environment for variable transfer
(org-babel-edit-prep:R): Added variable
org-babel-R-variable-environment-name which enables reverting to old
behaviour when transfering variables, i.e. in .GlobalEnv
(org-babel-expand-body:R): added reading R code from directory under
org tree

* etc/R/org_functions.R: Resorting to old behaviour when env==""
  insead of previously NULL