Asana-Math: close but no cigar

It's nice to see that the first (& only?) FOSS OpenType math font, (and by that I mean one that has a math script, like Cambria Math), has been added to rawhide. But the font is currently useless in Fedora, because (i) our XeTeX is too old, and (ii) the unicode-math XeLaTeX package is not installed. Unlike most other TeX projects, XeTeX has it's own SNV repository. I've been using the svn version of XeTeX for a while now, mainly because I've reported some bugs upstream (and I mean to the real upstream, not TeXLive). The repository includes all the required texmf bits that XeTeX needs, but unicode-math is considered experimental so it's not installed even by the svn installation script, thus it's missing even in TeXLive 2008. But it works well enough for me and others on that have tried it, including typesetting the whole AMS test document. Given that we package xetex separately in texlive-xetex, and since it doesn't seem likely that we'll ship TeXLive 2008 anytime soon, I'd like to prose that we switch xetex to its own upstream sources instead of getting the obsolete version from TeXLive 2007. This will fix (i) without having to wait for TeXLive 2008 to get packaged. Since we'd be using the svn sources, we can easily add unicode-math - it just needs some files copied to texmf, so we'd fix (ii) as well.