Bug 801909: Add validation to externalfiles.

* Move to a real management command.
* Add tests for updating and validation.
* Add ability to specify file class in settings.
Update a bunch of calendars for 2014

Bug 913379 - Updated Czech holidays file

Bug 1005069 - Date not according to spec in Dutch holiday calendar

Bug 1002035 - Haiti Holidays Calendar

Bug 936885 - Hong Kong Holidays 2007-2014

Bug 1001483 - Addition of Ireland Public Holidays 2014 to 2021

Bug 1015838 - Updated holiday calendar for Japan

Bug 1011883 - Morocco Holidays over (without religious holidays)

Bug 988735 - Holiday calendar for South Africa 2013-2021

Bug 1013063 - India calendar not download. Message displayed "Calendar not found on Server"
Change purchase URL for Alcatel OTF E. Bug 1042902.
Add O2 purchase link to Alcatel OTF E. Bug 1042500.
Merge pull request #2173 from jpetto/bug-1042902-change-alcatel-fire-e-purchase-url

Change purchase URL for Alcatel OTF E. Bug 1042902.
Bug 1043366 - Add Berlin office contact links
Merge pull request #2175 from craigcook/bug-1043366-berlin-office-links

Bug 1043366 - Add Berlin office contact links
Merge pull request #2169 from kewisch/holidays

Update a bunch of calendars for 2014
Merge pull request #2174 from jpetto/bug-1042500-add-de-o2-link-alcatel-otf-e

Add O2 purchase link to Alcatel OTF E. Bug 1042500.
Merge pull request #2164 from pmclanahan/fix-credits-missing-500-801909

Bug 801909: Add validation to externalfiles.
Remove DeprecationWarning about BaseException.message
Merge pull request #2177 from jgmize/remove-deprecated-message

Remove DeprecationWarning about BaseException.message
Add templates for /about/forums port for Bug 896474
Bug 896474: Generate forums from data file in SVN.
Output forum list with simpler markup Bug 896474
Revert Webmaker promo. Bug 1042126.

- New Webmaker promo markup/CSS/images left in repo for
  probable future use.
Merge pull request #2178 from jpetto/bug-1042126-revert-webmaker-promo

Revert Webmaker promo. Bug 1042126.
Merge pull request #2160 from mozilla/port-forums-new-896474

Bug Bug 896474: Port /about/forums
[fix bug 1040719] Stop redirecting Firefox Nightly First Run pages to Mozilla Taiwan website
Merge pull request #2182 from alexgibson/bug-1040719-firefox-nightly-firstrun-mozilla-taiwan

[fix bug 1040719] Stop redirecting Firefox Nightly First Run pages to Mozilla Taiwan website