win32 resource: allow custom comments field in DLL

Allow merges of files (and trees) with whitespace problems/fixes

clar: update to 08f434d

Update tips fixes

Lower case the include directive of windows header

PERF: In MERGE, lazily compute is_binary

Initialize refs vector in git_remote_update_tips().

Otherwise, bailing out early when ls_to_vector() fails accesses
uninitialized memory.

Add annotated versions of ref-modying functions

[WIP] Smarter pack-building

Don't ask for a stream's certificate unless it's encrypted

Fix git_submodule_sync writing URL to wrong key.

Since the Linux platform has a case sensitive file system, the header name should be lower case for cross compiling purposes. (On Linux, the mingw header is called ```windows.h```).

When the user has a certificate check callback set, we still have to
check whether the stream we're using is even capable of providing a
certificate.

In the case of an unencrypted certificate, do not ask for it from the
stream, and do not call the callback.

When we have an HTTP stream and have set the certificatre check
callback, we currently fail as we ask the unencrypted stream for its
certificate.

This also brings the soft-reset tests back to life. The function name
was missing an underscore, meaning they had not been running.

This extra constructor will be useful for the annotated versions of
ref-modifying functions, as it allows us to create a commit with the
extended sha syntax which was used to retrieve it.

We do not always want to put the id directly into the reflog, but we
want to speicfy what a user typed. For this use-case we provide
annotated version of a few functions which let the caller specify what
user-friendly name was used when asking for the operation.

Avoid retaining / releasing the index more than necessary when GIT_DIFF_...

It turns out that erroring out on duplicate commits is the right thing
to do, but git was not hitting the bug on the server-side.

Bring back a descriptive error message in case of duplicate entries and
error out.

If a packfile includes duplicate objects, we can choose to use the
secon copy instead of the first by using the same logic as if it were
the first.

Change the error condition from 0 to -1, which indicates a bad resize,
and set the OOM message in that case.

This does mean we will leak the first copy of the object. We can deal
with that later, but making fetches work is more important.

While this is not even close to a fix, we can at least set an error
message so we know which error we are facing. Up to know we just
returned an error without a message.

This was but down to 5 when GitHub made a change to their server which
made them stop honouring the include-tag request.

This has recently been corrected, so we can bring it back up to six.

local: create pack with multiple threads

Currently git_submodule_sync writes the submodule's URL to the
key 'branch.<REMOTE_NAME>.remote' while the reference
implementation of `git submodule sync` writes to
'remote.<REMOTE_NAME>.url', which is the intended behavior
according to git-submodule(1).

The current implementation does not set 'fire_callback' back to 0 for failed updates so the callback still fires.

Instead of adding yet another condition check to set 'fire_callback' to 0 if needed, considering this function should be a no-op for failed updates anyway, the best fix is to simplify its logic to check upfront if the update is a failed one.