Merge branch 'jl/submodule-diff'

* jl/submodule-diff:
  Performance optimization for detection of modified submodules
  git status: Show uncommitted submodule changes too when enabled
  Teach diff that modified submodule directory is dirty
  Show submodules as modified when they contain a dirty work tree

diff --cc diff.c
Simple merge

diff --cc revision.c
Simple merge

diff --cc submodule.c
index 3007f7d,3f851de..f657bee
--- 1/submodule.c
--- 2/submodule.c
+++ b/submodule.c
@@@ -4,8 -4,9 +4,9 @@@
  #include "diff.h"
  #include "commit.h"
  #include "revision.h"
+ #include "run-command.h"
  
 -int add_submodule_odb(const char *path)
 +static int add_submodule_odb(const char *path)
  {
        struct strbuf objects_directory = STRBUF_INIT;
        struct alternate_object_database *alt_odb;

diff --cc wt-status.c
Simple merge