* alloc.c (allocate_string) [macintosh]: Call check_string_bytes

* alloc.c (allocate_string) [macintosh]: Call check_string_bytes
only if current_sblock has been initialized.

* frame.c (Fdelete_frame) [macintosh]: Allow deletion of initial
terminal frame even if it is the only visible frame.

* src/macfns.c (QCconversion): Replaces QCalgorithm.

* src/macfns.c (image_ascent, lookup_image): Adapt to change of
image margins.

* src/macterm.c (x_produce_image_glyph, x_draw_image_foreground)
(x_draw_image_relief, x_draw_image_foreground_1)
(x_draw_image_glyph_string): Adapt to change of image margins.

* src/macterm.c (mac_to_x_fontname): Change charset name of
Simplify Chinese fonts from gb2312 to gb2312.1980 and Korean fonts
from ksc5601 to ksc5601.1989.