Handle remaining incorrect API translations in api_conv.pl.

Handle remaining incorrect API translations in api_conv.pl.

The big change is treating numbers as separate "words" in the
translation, which leads to funny-looking names like xcb_char_2_b_t, but
makes more sense than the alternative in other situations and was
suggested on the mailing list.

This version still disagrees with Vincent's last proposed XSL, but I
think my output is now preferable. Hopefully Josh has been thinking
along the same lines.