fetch_file_contents: reset all globals on start, return error message body when not using curl
subscribe_to_feed: report if cloudflare is in the error message
sanitize: allow <dfn> tag
### In brief
* Add `<dfn>` tag to allowed tags list
* `<dfn>` represents the defining instance of a term in HTML
* More [information about `<dfn>` on the w3school's website](http://www.w3schools.com/tags/tag_dfn.asp )
### Example
This stops article content such as...
```
Indian tea harvests are divided up by <dfn>flush</dfn>.
```
...from getting turned into...
```
Indian tea harvests are divided up by .
```
See merge request !45
Update af_comics plugin to support GoComics.
Updates the af_comics plugin to support new GoComics site, which dropped native RSS feeds.
See merge request !42
Third-party library upgrades
* lib: Upgrade php-gettext from 1.0.11 to 1.0.12
* lib: Upgrade accept-to-gettext.php from 2003-08-14 to 2007-04-01
* lib: Upgrade JShrink from 0.5.1 to 1.1.0
* lib: Upgrade mobile-detect from svn r44 (2012-05-03) to 2.8.24 (2016-11-11)
* lib: Upgrade php-publisher from ??? to a5d6a0e (2016-11-15)
* lib: Upgrade php-subscriber from ??? to 1213f89 (2016-11-15)
* lib: Upgrade script.aculo.us from 1.8.3 to 1.9.0
* lib: Upgrade timezones.txt from 2010k/l/m/n/2011a to 2016j
See merge request !40
lib: Upgrade Prototype from 1.7 to 1.7.3
Are you sure you want these as separate merge requests? The rest of the upgrades are much less invasive than Dojo, with essentially no changes outside of `lib`. I would of course leave them as separate commits in any case, but I had assumed they would be more convenient to test in one batch.
See merge request !39
https://www.iana.org/time-zones
The local change adding Automatic was preserved; the local change
removing Zulu was not.
Signed-off-by: Anders Kaseorg <andersk@mit.edu>
Andrew Dolgov