Add git_submodule_resolve_url()

corrected typo in error message

Update clar to e1990d6

Rename options structures

Add a tag example

Fun with memory access

Plug leaks

We look up a reference in order to figure out if it's the current
branch, which we need to free once we're done with the check.

As a bonus, only perform the check when we're passed the force flag, as
it's a useless check otherwise.

We can make use of git_object_dup to use refcounting instead of pointer
comparison to make sure we don't free the caller's object.

This also lets us simplify the case for '~0' which is now just an
assignment instead of looking up the object we have at hand.

Combinations of connect + fetch can call local_open multiple
times. Detect this and skip the initialization stage.

Previously the hunk_byfinalline_search_cmp function was called with different
data types (size_t and uint32_t) for the key argument but expected only the
former resulting in an invalid memory access when passed the latter on a 64 bit
machine.

The following patch makes sure that the function is called and works with the
same type (size_t).

Update clar to a0b00f0

MSVC doesn't like declaring variables in the middle of a block, so make
sure we only declare variables at the beginning of a block.

Revert pull request #1997

Fix GIT_MERGE_OPTS_INIT on MSVC.

Function-based options initializers

examples/diff:Add the shortstat flag to examples/diff.c

The basic structure of each function is courtesy of arrbee.

Add ODB API to check for existence by prefix and object id shortener

refdb: catch a directory disappearing

ODB writing fails gracefully when unsupported

If a directory disappears between the time we look up the entries of its
parent and the time when we go to look at it, we should ignore the error
and move forward.

This fixes #2046.

If no ODB backends support writing, we should fail gracefully.