expire time bug fixed, mendeley api lib on the core plugin file

Signed-off-by: Davide Parisi <davideparisi@gmail.com>
Basic shortcode process completed

Signed-off-by: Davide Parisi <davideparisi@gmail.com>
shortcodes improved with enclosing tag attribute and content for the heading

Signed-off-by: Davide Parisi <davideparisi@gmail.com>
Merge branch 'refs/heads/citeproc'

* refs/heads/citeproc:
  shortcodes improved with enclosing tag attribute and content for the heading
  Basic shortcode process completed
  expire time bug fixed, mendeley api lib on the core plugin file