Merge branch 'gc/config-context' into next

Reduce reliance on a global state in the config reading API.

* gc/config-context:
  config: pass source to config_parser_event_fn_t
  config: add kvi.path, use it to evaluate includes
  config.c: remove config_reader from configsets
  config: pass kvi to die_bad_number()
  trace2: plumb config kvi
  config.c: pass ctx with CLI config
  config: pass ctx with config files
  config.c: pass ctx in configsets
  config: add ctx arg to config_fn_t
  urlmatch.h: use config_fn_t type
  config: inline git_color_default_config

git-compat-util.h

@@ -440,8 +440,10 @@ typedef uintmax_t timestamp_t;
 #endif
 
 #ifndef platform_core_config
+struct config_context;
 static inline int noop_core_config(const char *var UNUSED,
 				   const char *value UNUSED,
+				   const struct config_context *ctx UNUSED,
 				   void *cb UNUSED)
 {
 	return 0;