Merge pull request #206 from labster/master

set wgFixDoubleRedirects to true on allthetropeswiki (only temporarily)
Add Math to jdwiki
png stuff for math
let's not break everything
Use LaTeXML
Set GPG passphrase to an empty string in backup script
Allow fonts to be loaded from Orain subdomains

Fixes #205
Allow PHP path splitting, e.g. /w/index.php/Foo

Fixes #203
Add support for group overrides, fixes #14

Based on the WMF implementation. I renamed groupOverrides2 to defaultGroupOverrides and groupOverrides to specificGroupOverrides for clarity.
Use group overrides for closed wikis
trainwiki -> reviwiki
Add prod1 as miscserver
add extensions to extloadwiki
enable on ATTwiki
Force archivoespiralwiki to be 'locked'
locking all wikis is bad
Move wiki archiving to a wmg var
Add debugging for sysadmins
Setting archivoespiral to Spanish by default
Allowing PDF uploads in spiralwiki