Fix `org-insert-heading' before first headline

* lisp/org.el (org-insert-heading): Fix error when inserting
  a headline before first headline, with point not at bol.  Remove
  source block check for consistency with behavior after first
  headline.  Tiny fix to docstring.

* testing/lisp/test-org.el (test-org/meta-return): Remove unnecessary
  test (not testing specifications).
(test-org/insert-heading): New test.
org.el (org-overview): Don't call `recenter'

* org.el (org-overview): Don't call `recenter'.

Thanks to Nicolas Richard for suggesting this.
org.el (org-insert-heading): Be more consistent in respecting content

* org.el (org-insert-heading): With one universal prefix
argument or `org-insert-heading-respect-content' set to `t',
always respect the content, i.e. don't insert a list item and
don't convert normal lines into headings.  Update docstring.
(org-insert-heading-respect-content): Remove unused arg.
(org-insert-todo-heading-respect-content): Don't use
`org-insert-todo-heading-respect-content', use the second
argument of `org-insert-todo-heading' instead.

* org-mobile.el (org-mobile-edit): Use only one arg.

Thanks to Bernt Hansen for reporting this.
Prefer `set-window-start' over `recenter' in some places.

* org-agenda.el (org-agenda-show-1):
* org-table.el (org-table-show-reference):
* org.el (org-fix-ellipsis-at-bol)
(org-first-headline-recenter): Use `set-window-start' instead
of `recenter'.

* org-agenda.el (org-recenter-heading): Delete.
org-agenda.el: Fix bug when redoing sticky agendas with log mode and/or clockreport mode on

* org-agenda.el (org-agenda-mode): Let `org-agenda-redo' DTRT
when agenda are sticky.
(org-agenda-tag-filter-while-redo): Delete.
(org-agenda-list, org-agenda-redo, org-agenda-filter-by-tag):
Remove unused code.
(org-agenda-clockreport-mode, org-agenda-set-mode-name): Don't
consider tag filters.

Thanks to Bernt Hansen for reporting this.
Fix 30220ff
fix semi-backend bug in org-mime

* contrib/lisp/org-mime.el (org-mime-multipart): Fix bug in use of the
  semi org-mime-library when converting emails to HTML.
org-macs: Remove restriction when locating markers

* org-macs.el: Remove restriction when locating markers

Allows org-with-point-at to locate point outside the current
restriction.
org-agenda.el (org-entries-lessp): Fix inactive timestamp comparison

* org-agenda.el (org-entries-lessp): Fix inactive timestamp
comparison.
org-agenda.el (org-cmp-ts): Fix agenda entry type checking

* org-agenda.el (org-cmp-ts): Fix agenda entry type checking.

Thanks to Trevor Murphy for reporting this.
org.el (org-fontify-meta-lines-and-blocks-1): Fix handling of `org-hidden-keywords'

* org.el (org-fontify-meta-lines-and-blocks-1): Fix handling
of `org-hidden-keywords'.

Thanks to Leu Zhe for reporting this.
org-agenda.el (org-agenda-filter-apply): Fix setting of `org-agenda-filtered-by-category'

* org-agenda.el (org-agenda-filter-apply): Fix setting of
`org-agenda-filtered-by-category'.
ox-koma-letter.el (koma-letter): Use `org-koma-letter-from-address'

* ox-koma-letter.el (koma-letter): Use
`org-koma-letter-from-address'.

TINYCHANGE
org.el: Delete `org-fix-ellipsis-at-bol'

* org.el (org-fix-ellipsis-at-bol): Delete.
(org-mode, org-show-context, org-isearch-end): Don't use
`org-fix-ellipsis-at-bol'.
Fix typos: backport revision r117377 from emacs trunk
org-get-wdays may return fractional number of days
org-deadline-close obeys sub-day "closeness."
org-deadline-close returns T for incomplete, overdue item.
Don't add so many newlines when archiving

This hopefully solves two cases:

1. Extra newline(s) when not archiving under a specific headline
2. Extra newline(s) when archiving under a specific headline.
Add :collapse-steps argument to clocktable

This lets me use :step but have each step generate rows in a single
table.