Merge branch 'jk/ref-filter-colors'

"%C(color name)" in the pretty print format always produced ANSI
color escape codes, which was an early design mistake.  They now
honor the configuration (e.g. "color.ui = never") and also tty-ness
of the output medium.

* jk/ref-filter-colors:
  ref-filter: consult want_color() before emitting colors
  pretty: respect color settings for %C placeholders
  rev-list: pass diffopt->use_colors through to pretty-print
  for-each-ref: load config earlier
  color: check color.ui in git_default_config()
  ref-filter: pass ref_format struct to atom parsers
  ref-filter: factor out the parsing of sorting atoms
  ref-filter: make parse_ref_filter_atom a private function
  ref-filter: provide a function for parsing sort options
  ref-filter: move need_color_reset_at_eol into ref_format
  ref-filter: abstract ref format into its own struct
  ref-filter: simplify automatic color reset
  t: use test_decode_color rather than literal ANSI codes
  docs/for-each-ref: update pointer to color syntax
  check return value of verify_ref_format()

config.c

@@ -16,6 +16,7 @@
 #include "string-list.h"
 #include "utf8.h"
 #include "dir.h"
+#include "color.h"
 
 struct config_source {
 	struct config_source *prev;
@@ -1350,6 +1351,9 @@ int git_default_config(const char *var, const char *value, void *dummy)
 	if (starts_with(var, "advice."))
 		return git_default_advice_config(var, value);
 
+	if (git_color_config(var, value, dummy) < 0)
+		return -1;
+
 	if (!strcmp(var, "pager.color") || !strcmp(var, "color.pager")) {
 		pager_use_color = git_config_bool(var,value);
 		return 0;