Merge branch 'ps/builtin-config-cleanup'

Code clean-up to reduce inter-function communication inside builtin/config.c done via the use of global variables. * ps/builtin-config-cleanup: (21 commits) builtin/config: pass data between callbacks via local variables builtin/config: convert flags to a local variable builtin/config: track "fixed value" option via flags only builtin/config: convert `key` to a local variable builtin/config: convert `key_regexp` to a local variable builtin/config: convert `regexp` to a local variable builtin/config: convert `value_pattern` to a local variable builtin/config: convert `do_not_match` to a local variable builtin/config: move `respect_includes_opt` into location options builtin/config: move default value into display options builtin/config: move type options into display options builtin/config: move display options into local variables builtin/config: move location options into local variables builtin/config: refactor functions to have common exit paths config: make the config source const builtin/config: check for writeability after source is set up builtin/config: move actions into `cmd_config_actions()` builtin/config: move legacy options into `cmd_config()` builtin/config: move subcommand options into `cmd_config()` builtin/config: move legacy mode into its own function ...