Use uniprop tables instead of biditype.h and bidimirror.h.

Use uniprop tables instead of biditype.h and bidimirror.h.

 src/bidi.c (bidi_initialize): Use uniprop_table instead of including
 biditype.h and bidimirror.h.
 src/biditype.h: File removed.
 src/bidimirror.h: File removed.
 src/deps.mk (bidi.o): Remove biditype.h and
 bidimirror.h.
 src/makefile.w32-in ($(BLD)/bidi.$(O)): Remove biditype.h and
 bidimirror.h.
 src/dispextern.h: Fix a typo in the comment to bidi_type_t.
 src/chartab.c: Improve commentary for the uniprop_table API.

 admin/unidata/bidimirror.awk: File removed.
 admin/unidata/biditype.awk: File removed.
 admin/unidata/makefile.w32-in (all): Remove src/biditype.h and
 src/bidimirror.h.
 (../../src/biditype.h, ../../src/bidimirror.h): Deleted.
 admin/unidata/Makefile.in (all): Remove src/biditype.h and
 src/bidimirror.h.
 (../../src/biditype.h, ../../src/bidimirror.h): Deleted.