[dev-context] Math accents

Math accents seems to be broken in all OpenType math fonts: * wide accents don't show at all; ConTeXt is looking for non-existent characters (U+FE302 for example). * regular accents don't work with Asana because ConTeXt is looking for the spacing accents which it does not have I think this is left over from the hack of using modifier accents for non-growing ones and combining accents for the growing. Now since luatex introduced new keywords to handle this, I propose that all math accents use the combining accents (which is the right thing to do for all fonts any way) and non growing one would use the new "fixed" keyword. Attached a simple test file. Regards, Khaled -- Khaled Hosny Egyptian Arab