[Fontconfig] FontConfig iso15924 tag for autoinstallation via PackageKit

[Frédéric WANG]

Dear FontConfig & PackageKit developers,

I've recently worked on automatic font installation in Gecko-based 
applications using PackageKit [1]. The current patch to add 
notifications for missing glyphs in Gecko relies on script tags as 
defined in iso15924 [2] [3]. So it would help if fontconfig & PackageKit 
would be able to handle some metadata for these script tags, for example 
:script=Khmr (at the moment I think only the :lang tag is supported). 
Also, I'm interested in automatic installation of math fonts, so it 
would be important to support the code "Zmth=Mathematical notation" too. 
This script does not correspond to any Unicode script, but you can find 
some relevant ranges in http://www.w3.org/TR/xml-entity-names/#blocks 
(especially the Mathematical Alphanumeric Symbols are important and are 
required for [4])

Thanks,

[1] https://bugzilla.mozilla.org/show_bug.cgi?id=467729
[2] http://www.unicode.org/iso15924/iso15924-codes.html
[3] https://bugzilla.mozilla.org/show_bug.cgi?id=619521
[4] https://bugzilla.mozilla.org/show_bug.cgi?id=930504

-- 
Frédéric Wang
MathML Crowdfunding: ulule.com/mathematics-ebooks