Johan Herland authored Jul 13, 2010 and Junio C Hamano committed Jul 13, 2010

Currently, the graph code is hardcoded to use ANSI color escapes for
coloring the column characters in the generated graphs. This patch
allows a custom scheme of colors to be set at runtime, allowing
different types of color escapes to be used.

A new function - graph_set_column_colors() - is added to the graph.h API,
which allows a custom column_colors array (and column_colors_max value)
to replace the builtin ANSI array (and _max value). The new function -
if used - must be called before graph_init() is called.

Signed-off-by: Johan Herland <johan@herland.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>