Fix escaping of links in html export.

* lisp/ox-html.el (org-html-link): Unescape org-escaped links an
  re-escape for html (browser).
Merge branch 'maint'
org-colview.el (org-columns-display-here): Fix column view

* org-colview.el (org-columns-display-here): Fix the column
view for numbers with a format specifier (e.g. {+; %5.1f}).

Thanks to OSiUX and Michael Brand for reporting this.
Merge branch 'maint'
org.texi: Column attributes format specifier

* doc/org.texi (Column attributes): Add a sentence to point out the
dependency on the format specifier.
Merge branch 'maint'
org.texi: Fix typo
Merge branch 'maint'
ox-md: Generate md links to other Org files

* lisp/ox-md.el (org-md-link): Generate md links to other Org files
  instead of html links.

Thanks to Mark Janssen for suggesting it.
Merge branch 'maint'
Add ERT for TBLFM with sub-total

* testing/lisp/test-org-table.el (test-org-table/sub-total): Add a use
case of grouped rows with sub-total.
org-element: Fix inlinetask parsing

* lisp/org-element.el (org-element-inlinetask-parser): Fix parsing
  when regular and degenerate inlinetasks are mixed in the section.
* testing/lisp/test-org-element.el (test-org-element/inlinetask-parser):
  Add tests.

Thanks to Anders Johansson for reporting it.
Merge branch 'maint'
org-feed.el: Allow current buffer to be indirect

* lisp/org-feed.el (org-feed-alist): Allow current buffer to be an
indirect buffer.
Improve message when file to include is missing

* org.el (org-file-contents): Improve message when linked file does not exist.
Update org-drill to the latest version.
Fix escaping of more links in HTML export

* lisp/org.el (org-link-escape-chars): Extend docstring.
(org-link-escape-chars-browser): Mention in docstring that it will
become a candidate for removal.
(org-link-escape-browser): Mention in docstring that it will become a
candidate for removal.
(org-open-at-point): Move `url-encode-url' and comments into
`org-link-escape-browser'.

* lisp/ox-html.el (org-html-link): Make use of
`org-link-escape-browser' like `org-open-at-point'.

* testing/lisp/test-org.el (test-org/org-link-escape-chars-browser):
Mention in docstring that it will become a candidate for removal.
Simplify ERT for TBLFM with sub-total

* testing/lisp/test-org-table.el (test-org-table/sub-total): Simplify
condition in "if".
org-element: Implement lazy cache synchronization

* lisp/org-element.el (org-element-cache-sync-idle-time): Change
  default value.
(org-element-cache-sync-duration, org-element-cache-sync-break,
org-element--cache-sync-requests, org-element--cache-sync-timer,
org-element--cache-sync-keys, org-element--cache-default-key,
org-element--cache-change-warning): New variables.
(org-element-cache-merge-changes-threshold,
org-element--cache-status): Removed variables.
(org-element--cache-key, org-element--cache-generate-key,
org-element--cache-key-less-p, org-element--cache-find,
org-element--cache-set-timer, org-element--cache-process-request,
org-element--cache-submit-request, org-element--parse-to,
org-element--cache-interrupt-p, org-element--cache-put,
org-element--cache-active-p): New functions.
(org-element--cache-compare): Adapt to new keys in AVL tree.
(org-element--cache-pending-changes-p,
org-element--cache-cancel-changes, org-element--cache-mapc,
org-element-cache-get, org-element-cache-put): Removed functions.
(org-element--cache-before-change): Use new variables.
(org-element--cache-after-change): Renamed from
`org-element--cache-record-change'.
(org-element-cache-get): Change signature.
(org-element-cache-put): Rewrite function.  Use new tools.
(org-element-cache-reset): Adapt to new variables.
(org-element--cache-sync): Rewrite function.

* lisp/ox.el (org-export--generate-copy-script): Do not copy through
  new cache-related variables.
(org-export-ignored-local-variables): New variable.

* testing/lisp/test-org-element.el (test-org-element/cache): New test.

Now only the part of the cache that needs to be accessed is updated
synchronously.  Otherwise, it happens on idle time.
org-element: Fix cache bug

* lisp/org-element.el (org-element--parse-to): Fix cache parsing when
  the next element to shift is at the contents beginning of its
  parent.  Refactor function.