Merge branch 'nd/complete-config-vars'

Continuing with the idea to programatically enumerate various
pieces of data required for command line completion, teach the
codebase to report the list of configuration variables
subcommands care about to help complete them.

* nd/complete-config-vars:
completion: complete general config vars in two steps
log-tree: allow to customize 'grafted' color
completion: support case-insensitive config vars
completion: keep other config var completion in camelCase
completion: drop the hard coded list of config vars
am: move advice.amWorkDir parsing back to advice.c
advice: keep config name in camelCase in advice_config[]
fsck: produce camelCase config key names
help: add --config to list all available config
fsck: factor out msg_id_info[] lazy initialization code
grep: keep all colors in an array
Add and use generic name->id mapping code for color slot parsing

diff --cc Documentation/config.txt
Simple merge

diff --cc builtin/am.c
Simple merge

diff --cc builtin/branch.c
Simple merge

diff --cc builtin/commit.c
Simple merge

diff --cc config.c
Simple merge

diff --cc contrib/completion/git-completion.bash
Simple merge

diff --cc diff.c
Simple merge

diff --cc fsck.c
index 48e7e36869a7cbcb47e2e2a0401dd1047612e5d7,c2b8974c0e6a1553616093f5120123ce59d3b20d..0b8b20b6c464cdfbbb8afd9685f45e3e2e67adfa
--- 1/fsck.c
--- 2/fsck.c
+++ b/fsck.c
@@@ -10,14 -10,8 +10,15 @@@
  #include "utf8.h"
  #include "sha1-array.h"
  #include "decorate.h"
 +#include "oidset.h"
 +#include "packfile.h"
 +#include "submodule-config.h"
 +#include "config.h"
+ #include "help.h"
  
 +static struct oidset gitmodules_found = OIDSET_INIT;
 +static struct oidset gitmodules_done = OIDSET_INIT;
 +
  #define FSCK_FATAL -1
  #define FSCK_INFO -2
  

diff --cc grep.c
Simple merge

diff --cc log-tree.c
Simple merge