Add GIT_COLOR_BOLD_* macros to set both bold and the color in one
sequence. This saves two characters of output ("ESC [ m", minus ";")
and makes the code more readable.
Add the remaining GIT_COLOR_BG_* macros to make the list complete.
The white and black colors are not included since they look bad on most
Signed-off-by: Mark Lodato <email@example.com>
Signed-off-by: Junio C Hamano <firstname.lastname@example.org>