Signed-off-by: schu <schu-github@schulog.org>

Ensure that all memory related functions (malloc, calloc, strdup, free,
etc) are using their respective `git__` wrappers.

1. The license header is technically not valid if it doesn't have a
copyright signature.

2. The COPYING file has been updated with the different licenses used in
the project.

3. The full GPLv2 header in each file annoys me.

This will make libgit2 more suitable for embedding.

Given that the sha1.h header file should never be included into
any other file, since it represents an implementation detail of
hash.c, we remove the header and inline it's content.

Signed-off-by: Ramsay Jones <ramsay@ramsay1.demon.co.uk>

Signed-off-by: Ramsay Jones <ramsay@ramsay1.demon.co.uk>

Since block-sha1 from git.git has such excellent performance, we
can also get rid of the openssl dependency. It's rather simple
to add it back later as an optional extra, but we really needn't
bother to pull in the entire ssl library and have to deal with
linking issues now that we have the portable and, performance-wise,
truly excellent block-sha1 code to fall back on.

Since this requires a slight revamp of the build rules anyway, we
take the opportunity to fix including EXTRA_OBJS in the final build
as well.

The block-sha1 code was originally implemented for git.git by
Linus Torvalds <torvalds@linux-foundation.org> and was later
polished by Nicolas Pitre <nico@cam.org>.

Signed-off-by: Andreas Ericsson <ae@op5.se>

Paul agreed to the GCC-exception license by email:
|
| From: Paul Kocher <paul@cryptography.com>
| Date: Sun, 15 Mar 2009 11:37:23 -0700
| Subject: Re: Adding Mozilla SHA1 implementation to libgit2
|
| Yes - that's fine.
|
| At 01:56 AM 3/5/2009, Andreas Ericsson wrote:
| > Hi Paul. We spoke earlier about this, if you remember?
| > We'd like to add the GCC-exception to the GPL license
| > for these files.

Signed-off-by: Paul Kocher <paul@cryptography.com>
Signed-off-by: Ramsay Jones <ramsay@ramsay1.demon.co.uk>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

We now forbid direct use of malloc, strdup or calloc within the
library and instead use wrapper functions git__malloc, etc. to
invoke the underlying library malloc and set git_errno to a no
memory error code if the allocation fails.

In the future once we have pack objects in memory we are likely
to enhance these routines with garbage collection logic to purge
cached pack data when allocations fail.  Because the size of the
function will grow somewhat large, we don't want to mark them for
inline as gcc tends to aggressively inline, creating larger than
expected executables.

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

[sp: Changed signature for output to use git_oid, and added
     a test case to verify an allocated git_hash_ctx can be
     reinitialized and reused.]

Signed-off-by: Ramsay Jones <ramsay@ramsay1.demon.co.uk>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>