Merge branch 'cw/strbuf-cleanup'

Move functions that are not about pure string manipulation out of
strbuf.[ch]

* cw/strbuf-cleanup:
  strbuf: remove global variable
  path: move related function to path
  object-name: move related functions to object-name
  credential-store: move related functions to credential-store file
  abspath: move related functions to abspath
  strbuf: clarify dependency
  strbuf: clarify API boundary

dir.h

@@ -7,6 +7,8 @@
 #include "statinfo.h"
 #include "strbuf.h"
 
+struct repository;
+
 /**
  * The directory listing API is used to enumerate paths in the work tree,
  * optionally taking `.git/info/exclude` and `.gitignore` files per directory
@@ -41,6 +43,8 @@
  *
  */
 
+struct repository;
+
 struct dir_entry {
 	unsigned int len;
 	char name[FLEX_ARRAY]; /* more */