[dev-context] \sqrt in expansions bug

Hi, Macros that use \doifnextcharelse should all be defined as \unexpanded, to prevent errors like: \expanded{$\sqrt 2$} Also affected are: \decrement \increment maybe there are others, but these were easy to spot because they were single-line \def's. The \sqrt is painful, because it is likely to appear in \write-s Cheers, Taco