Merge branch 'jc/cache-tree'

* jc/cache-tree: (26 commits)
  builtin-rm: squelch compiler warnings.
  git-write-tree writes garbage on sparc64
  Fix crash when reading the empty tree
  fsck-objects: do not segfault on missing tree in cache-tree
  cache-tree: a bit more debugging support.
  read-tree: invalidate cache-tree entry when a new index entry is added.
  Fix test-dump-cache-tree in one-tree disappeared case.
  fsck-objects: mark objects reachable from cache-tree
  cache-tree: replace a sscanf() by two strtol() calls
  cache-tree.c: typefix
  test-dump-cache-tree: validate the cached data as well.
  cache_tree_update: give an option to update cache-tree only.
  read-tree: teach 1-way merege and plain read to prime cache-tree.
  read-tree: teach 1 and 2 way merges about cache-tree.
  update-index: when --unresolve, smudge the relevant cache-tree entries.
  test-dump-cache-tree: report number of subtrees.
  cache-tree: sort the subtree entries.
  Teach fsck-objects about cache-tree.
  index: make the index file format extensible.
  cache-tree: protect against "git prune".
  ...

Conflicts:

	Makefile, builtin.h, git.c: resolved the same way as in next.

diff --cc .gitignore
Simple merge

diff --cc Makefile
Simple merge

diff --cc builtin-apply.c
Simple merge

diff --cc builtin-read-tree.c
index ec40d013c4d8508bfd10d75e2dab3090dea64a45,99e7c750444117fe07b25bd75d454f03da2134fe..716f7925142bca11cf7ab5438ce5908e55285463
--- 1/builtin-read-tree.c
--- 2/read-tree.c
+++ b/builtin-read-tree.c
@@@ -9,9 -9,9 +9,10 @@@
  
  #include "object.h"
  #include "tree.h"
+ #include "cache-tree.h"
  #include <sys/time.h>
  #include <signal.h>
 +#include "builtin.h"
  
  static int reset = 0;
  static int merge = 0;

diff --cc cache.h
Simple merge