To remove extremas of vertical strokes of CJK Ideographs at
low resolution and make the top and bottom horizontal stems
aligned, bluezones for CJK Ideographs are calculated from
sample glyphs.  At present, vertical bluezones (bluezones
to align vertical stems) are disabled by default.  For detail, see
http://lists.gnu.org/archive/html/freetype-devel/2011-04/msg00070.html
http://lists.gnu.org/archive/html/freetype-devel/2011-04/msg00092.html
http://lists.gnu.org/archive/html/freetype-devel/2011-05/msg00001.html

* include/freetype/internal/fttrace.h: New trace component `afcjk'.
* src/autofit/afcjk.h (AF_CJK{Blue,Axis,Metric}Rec): Add CJK version
for AF_Latin{Blue,Axis,Metric}Rec.
(af_cjk_metrics_check_digits): Ditto, shared with Indic module.
(af_cjk_metrics_init_widths): Ditto.
(af_cjk_metrics_init): Take AF_CJKMetric instead of AF_LatinMetric.
(af_cjk_metrics_scale): Ditto (declaration).
(af_cjk_hints_init): Ditto (declaration).
(af_cjk_hints_apply): Ditto (declaration).
* src/autofit/afcjk.c (af_cjk_metrics_scale): Ditto (body).
(af_cjk_hints_init): Ditto (body).
(af_cjk_hints_apply): Ditto (body).
(af_cjk_metrics_init_widths): Duplicate af_latin_metrics_init_widths.
(af_cjk_metrics_check_digits): Duplicate af_latin_metrics_check_digits.
(af_cjk_metrics_init): Call CJK bluezone initializer.
(af_cjk_metrics_scale_dim): Add code to scale bluezones.
(af_cjk_hints_compute_blue_edges): New function, CJK version of
af_latin_hints_compute_blue_edges.
(af_cjk_metrics_init_blues): New function, CJK version of
af_latin_metrics_init_blues.
(af_cjk_hints_edges): Add code to align the edge stems to blue zones.

* src/autofit/afindic.c (af_indic_metrics_init): Take AF_CJKMetric
instead of AF_LatinMetric, and initialize as af_cjk_metrics_init.
However bluezones are not initialized.
(af_indic_metrics_scale): Take AF_CJKMetric instead of AF_LatinMetric.
(af_indic_hints_init): Ditto.
(af_indic_hints_apply): Ditto.

* docs/CHANGES: Note about CJK bluezone support.