editor: move editor-related functions and declarations into common file

cache.h and strbuf.[ch] had editor-related functions.  Move these into
editor.[ch].

Signed-off-by: Elijah Newren <newren@gmail.com>
Acked-by: Calvin Wan <calvinwan@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/builtin/add.c b/builtin/add.c
index d3c51e2..76cc026 100644
--- a/builtin/add.c
+++ b/builtin/add.c
@@ -9,6 +9,7 @@
 #include "config.h"
 #include "builtin.h"
 #include "lockfile.h"
+#include "editor.h"
 #include "dir.h"
 #include "gettext.h"
 #include "pathspec.h"
diff --git a/builtin/am.c b/builtin/am.c
index 0d7ee28..f7a065e 100644
--- a/builtin/am.c
+++ b/builtin/am.c
@@ -9,6 +9,7 @@
 #include "advice.h"
 #include "config.h"
 #include "builtin.h"
+#include "editor.h"
 #include "environment.h"
 #include "exec-cmd.h"
 #include "gettext.h"
diff --git a/builtin/branch.c b/builtin/branch.c
index 7c1c872..1fb11d5 100644
--- a/builtin/branch.c
+++ b/builtin/branch.c
@@ -8,6 +8,7 @@
 #include "cache.h"
 #include "config.h"
 #include "color.h"
+#include "editor.h"
 #include "environment.h"
 #include "refs.h"
 #include "commit.h"
diff --git a/builtin/bugreport.c b/builtin/bugreport.c
index 03fb053..daf6c23 100644
--- a/builtin/bugreport.c
+++ b/builtin/bugreport.c
@@ -1,5 +1,6 @@
 #include "builtin.h"
 #include "abspath.h"
+#include "editor.h"
 #include "gettext.h"
 #include "parse-options.h"
 #include "strbuf.h"
diff --git a/builtin/commit.c b/builtin/commit.c
index 682f47c..e67c4be 100644
--- a/builtin/commit.c
+++ b/builtin/commit.c
@@ -13,6 +13,7 @@
 #include "cache-tree.h"
 #include "color.h"
 #include "dir.h"
+#include "editor.h"
 #include "environment.h"
 #include "builtin.h"
 #include "diff.h"
diff --git a/builtin/config.c b/builtin/config.c
index fe79fb6..9401f1e 100644
--- a/builtin/config.c
+++ b/builtin/config.c
@@ -3,6 +3,7 @@
 #include "alloc.h"
 #include "config.h"
 #include "color.h"
+#include "editor.h"
 #include "environment.h"
 #include "gettext.h"
 #include "ident.h"
diff --git a/builtin/merge.c b/builtin/merge.c
index 693f185..8da3e46 100644
--- a/builtin/merge.c
+++ b/builtin/merge.c
@@ -12,6 +12,7 @@
 #include "advice.h"
 #include "alloc.h"
 #include "config.h"
+#include "editor.h"
 #include "environment.h"
 #include "gettext.h"
 #include "hex.h"
diff --git a/builtin/notes.c b/builtin/notes.c
index 896140b..d578835 100644
--- a/builtin/notes.c
+++ b/builtin/notes.c
@@ -10,6 +10,7 @@
 #include "cache.h"
 #include "config.h"
 #include "builtin.h"
+#include "editor.h"
 #include "gettext.h"
 #include "hex.h"
 #include "notes.h"
diff --git a/builtin/replace.c b/builtin/replace.c
index f4b3a8e..981f189 100644
--- a/builtin/replace.c
+++ b/builtin/replace.c
@@ -11,6 +11,7 @@
 #include "cache.h"
 #include "config.h"
 #include "builtin.h"
+#include "editor.h"
 #include "environment.h"
 #include "gettext.h"
 #include "hex.h"
diff --git a/builtin/tag.c b/builtin/tag.c
index 88a2590..7d189a4 100644
--- a/builtin/tag.c
+++ b/builtin/tag.c
@@ -10,6 +10,7 @@
 #include "advice.h"
 #include "config.h"
 #include "builtin.h"
+#include "editor.h"
 #include "environment.h"
 #include "gettext.h"
 #include "hex.h"
diff --git a/builtin/var.c b/builtin/var.c
index d9943be..90616cf 100644
--- a/builtin/var.c
+++ b/builtin/var.c
@@ -5,6 +5,7 @@
  */
 #include "builtin.h"
 #include "config.h"
+#include "editor.h"
 #include "ident.h"
 #include "refs.h"