nls: use a slash instead of a combining solidus in compose sequences

First: combining diacritics like the combining long solidus (U+0338) are not meant to be used in compose sequences. Second: there is just one layout in xkeyboard-config that contains the U0338 character: the deprecated/obsolete German T3 layout. So, practically speaking, these compose sequences with U0338 were untypable. So, use a slash instead, that almost all layouts have. This does require that the sequence <Compose> <less> <slash> changes its meaning from backslash to not-less-than (≮). This seems like an acceptable sacrifice, as the sequence <Compose> <slash> <slash> is a faster/easier sequence for the backslash and most layouts contain a backslash already anyway.

Signed-off-by: Benno Schulenberg bensberg@telfort.nl