Fix check-box toggling when point is on a link at an item

* lisp/org.el (org-ctrl-c-ctrl-c): When using C-c C-c at an item with
  point on a link, make sure checkbox, if any, is toggled.

Reported-by: Christoph LANGE <math.semantic.web@gmail.com>
Merge branch 'maint'
ob-clojure.el: switch to nREPL as the main method of evaluating Clojure.

Get the old behavior with:
(defalias 'org-babel-execute:clojure 'org-babel--execute-clojure-slime)
ob-clojure nrepl customization variable

  - ensure body is expanded for n-repl as well
  - declare n-repl functions
  - remove require ob-tangle from ob-clojure

* lisp/ob-clojure.el (org-babel-clojure-backend): Customization
  variable to select clojure backend
  (nrepl-eval): Declared function.
  (nrepl-current-connection-buffer): Declared function.
  (org-babel-execute:clojure): Execution now uses customized backend.
ox-beamer: Protect fragile commands in sections

* lisp/ox-beamer.el (org-beamer--format-section): Protect fragile
  commands in sections.
Merge branch 'maint'
org-list: Fix misleading docstring

* lisp/org-list.el (org-list-allow-alphabetical): Remove reference to
  unused VALUE.
Merge branch 'maint'