Fix keysym2ucs lookup
Fix keysym2ucs lookup

The ucs2keysym table cannot be sorted both by ucs value *and* by keysym
value. It happens to be sorted by ucs value, so replace keysym binary
search with linear search.

This fixes the event_string for various characters.

GNOME/at-spi2-core,GNOME/at-spi2-core,GNOME/at-spi2-core