Added note about Pelican 3.5 to Assets README
incorrect property on article.series

`article.series.series` changed to `article.series.name` so it actually shows the name.
Merge pull request #360 from iKevinY/patch-1

Add note about Pelican 3.5 to Assets plugin documentation
Fixed "CRITICAL: can't compare offset-naive and offset-aware datetimes" bug

This is similar to another issue in a different plugin:
https://github.com/getpelican/pelican-plugins/issues/264
Merge pull request #372 from kylebarlow/master

filetime_from_git plugin: add timezone information to datetime objects
Merge pull request #365 from doobeh/master

incorrect property on article.series
update of pandoc_reader:

 * Add PANDOC_EXTENSIONS configuration variable, allowing one to
   enable or disable Pandoc's markdown extensions individually.
 * Remove dependency on pypandoc.
 * Don't change the working directory.
 * More efficient metadata extraction.
 * support more markdown file extensions
Merge pull request #373 from liob/pandoc_reader

update of pandoc_reader
Fix share_post plugin

Firstly, the implemented services only accept unmarked
text, so `get_text()` instead of `prettify()` is called.

Secondly, `&amp;` is properly escaped ampersand in href URLs.
Merge pull request #379 from kernc/share_post_fixes

Fix share_post plugin