Merge branch 'en/header-split-cache-h'

Header clean-up.

* en/header-split-cache-h: (24 commits)
  protocol.h: move definition of DEFAULT_GIT_PORT from cache.h
  mailmap, quote: move declarations of global vars to correct unit
  treewide: reduce includes of cache.h in other headers
  treewide: remove double forward declaration of read_in_full
  cache.h: remove unnecessary includes
  treewide: remove cache.h inclusion due to pager.h changes
  pager.h: move declarations for pager.c functions from cache.h
  treewide: remove cache.h inclusion due to editor.h changes
  editor: move editor-related functions and declarations into common file
  treewide: remove cache.h inclusion due to object.h changes
  object.h: move some inline functions and defines from cache.h
  treewide: remove cache.h inclusion due to object-file.h changes
  object-file.h: move declarations for object-file.c functions from cache.h
  treewide: remove cache.h inclusion due to git-zlib changes
  git-zlib: move declarations for git-zlib functions from cache.h
  treewide: remove cache.h inclusion due to object-name.h changes
  object-name.h: move declarations for object-name.c functions from cache.h
  treewide: remove unnecessary cache.h inclusion
  treewide: be explicit about dependence on mem-pool.h
  treewide: be explicit about dependence on oid-array.h
  ...

git-compat-util.h

@@ -878,12 +878,6 @@ int git_lstat(const char *, struct stat *);
 #define pread git_pread
 ssize_t git_pread(int fd, void *buf, size_t count, off_t offset);
 #endif
-/*
- * Forward decl that will remind us if its twin in cache.h changes.
- * This function is used in compat/pread.c.  But we can't include
- * cache.h there.
- */
-ssize_t read_in_full(int fd, void *buf, size_t count);
 
 #ifdef NO_SETENV
 #define setenv gitsetenv