[PATCH 0/4] Build in some more things

The main effect of this series is removing the fork/exec from pushing via the git protocol (aside from the later fork/exec in connect.c of course).

It also heads off some tempting transport-related fetch bugs, which I will not introduce in a later patch.

* Miscellaneous const changes and utilities
  Adds two small utility functions, and marks a bunch of stuff as const; 
  the const stuff is to keep builtin-fetch from getting messed up without 
  a warning, because it wants some lists not to change.

* Build-in peek-remote, using transport infrastructure.
* Build-in send-pack, with an API for other programs to call.
* Use built-in send-pack.

 Makefile                               |    4 ++-
 builtin-fetch.c                        |   10 +++---
 peek-remote.c => builtin-peek-remote.c |   55 +++++++++++++---------------
 send-pack.c => builtin-send-pack.c     |   46 ++++++++++++++++--------
 builtin.h                              |    2 +
 cache.h                                |    2 +-
 connect.c                              |   10 +++++-
 git.c                                  |    2 +
 http-push.c                            |    2 +-
 remote.c                               |   32 +++++++++++-----
 remote.h                               |   10 ++++--
 send-pack.h                            |   18 +++++++++
 transport.c                            |   63 +++++++++-----------------------
 transport.h                            |    6 ++--
 14 files changed, 146 insertions(+), 116 deletions(-)

	-Daniel
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