Auto-script selection for non-Latin fonts

[wspr]

In the function \fontspec_set_scriptlang:, if there hasn't been a script specified by the user then it tries to load the LATN script and gives a warning if this doesn't work.

This isn't friendly for non-Latin fonts. We should instead choose the first script in the font, perhaps with an info message.

[Pomax]

another case of the infinite latin recursion... http://tug.org/pipermail/xetex/2010-November/019265.html

[Pomax]

probably no longer relevant?

[khaledhosny]

XeTeX does this by default now, but I don’t think luaotfload does, if it does then we can drop that code entirely from fontspec since it is much harder to do from this level.