org-table.el (org-table-recalculate): Generate user error if an hline relative reference is use on the LHS of a formula

* org-table.el (org-table-recalculate): Generate user error if
an hline relative reference is use on the LHS of a formula.

TINYCHANGE
Some clean-up related to org-remember being removed

* org.el (org-directory, org-default-notes-file)
(org-reverse-note-order): Don't use the `org-remember'
customization group.
(org-require-autoloaded-modules): Don't require
`org-remember'.

* org-capture.el: Update commentary section to reflect the
fact that org-remember.el is not used anymore.
Merge branch 'maint'