[tex4ht] Huge update of tex4ht-fonts-noncjk.tex

[Karl Berry]

    for example I've tried to make fonts for `LGR` fontenc 

Looks like Eitan defined some lgr-related aliases for libertine, e.g.,
tex4ht/ht-fonts/alias/libertine/fxlri-xl-lgr.htf
contains the two lines:
---
.fxlr-xl-lgr
htfcss: fxlri-xl-lgrs font-style:italic;
---

So maybe other fonts can point to .fxlr-xl-lgr?

Also, FWIW, the gfs fonts (gfsdidot, gfsbodoni, etc.) support LGR, also
cbfonts.  They don't have htf files, but maybe htfgen could actually
work.  I know a couple of good people who can answer Greek-specific
questions (but know nothing in particular about tex4ht), if they can help.

Thanks,
Karl