Documentation fix

* doc/org.texi (Include files):
* doc/orgguide.texi (Include files): Remove reference to non-existent
  "quote" markup.
org-list: Fix typo in docstring

* lisp/org-list.el (org-list-repair): Fix typo in docstring.
org-footnote: forward declare functions

* lisp/org-footnote.el: Forward declare `org-element-context',
  `org-element-property' and `org-element-type'.

Introduced with 51e1131ff8.
Reverting "org-footnote: forward declare functions"
Revert "org-footnote: forward declare functions"

This reverts commit 814188ac7e25c500433c13d8696af47d62f0de23.

Accidentally applied to the wrong branch.
org.texi: Add f-1 to TBLFM example about nan

* doc/org.texi (Formula syntax for Calc): Add `f-1' to TBLFM example
about `nan'.
org.el: Fix setting and deleting properties with a null value

* org.el (org-property-re): Also match null properties by
default.
(org-entry-delete): Also delete null properties.
(org-read-property-value): Allow the empty string as a new
value.
(org-delete-property): Throw a message when there is not
property to delete.

Thanks to Andrea Rossetti for reporting this.
org-agenda.el (org-agenda-custom-commands-local-options): Fix misquoted values

* org-agenda.el (org-agenda-custom-commands-local-options):
Fix misquoted values.

Thanks to Thomas Morgan for reporting this.
Makefile: remove empty line in help output

* Makefile (help helpall): Remove empty line in help output.
mk/server.mk: add testing/ directory to distribution tarball

* mk/server.mk (ORGFULL): Add testing/ directory to distribution
  tarball.
ox: Fix priority bug in :title property

* lisp/ox.el (org-export--get-inbuffer-options): Return the empty
  string instead of nil when TITLE keywords has no value.
(org-export--get-buffer-attributes): Do not set :title property
early.
(org-export--get-global-options): Do not ignore anymore nil values.
Small refactoring.
(org-export-as): Correctly set :title here.

Thanks to Nicolas Richard for reporting it.
http://permalink.gmane.org/gmane.emacs.orgmode/87149
Fix typo

* lisp/org.el (org-scan-tags): Fix typo in docstring.