Fix some "attributes" related issues

The value returned by MultiByteToWideChar includes the NULL termination character.

Add missing semicolon

Conflicts:
	tests-clay/clay.h
	tests-clay/clay_main.c

Conflicts:
	tests-clay/clay_main.c

`delete` is a reserved keyword in C++.

This updates to implementation of gitattribute macros to be much more
similar to core git (albeit not 100%) and to handle expansion of
macros within macros, etc.  It also cleans up the refcounting usage
with macros to be much cleaner.

Also, this adds a new vector function `git_vector_insert_sorted()`
which allows you to maintain a sorted list as you go.  In order to
write that function, this changes the function `git__bsearch()` to
take a somewhat different set of parameters, although the core
functionality is still the same.

Currently, diff_index passes the full relative path from the
repository root to the callback. In case of an addition, it passes
the tree entry instead of the index entry.

This change fixes the path used for addition, and it passes only
the basename of the path. This mimics the current behavior of
git_tree_diff.

For the diff-index tests, the diff_more test will run multiple
times. Reset the expect_idx counter after each test in order to
allow this.

The git.git implementation allows this, and there is no reason not
to.

The clay test suite files clay.h and clay_main.c are generated by
the clay python script. Teach CMake about this dependency and
remove the generated files from the repository.

Add support for git attribute macro definitions.  Also, add
support for cache flush API to clear the attribute file content
cache when needed.

Additionally, improved the handling of global and system files,
making common utility functions in fileops and converting config
and attr to both use the common functions.

Adds a bunch more tests and fixed some memory leaks.  Note that
adding macros required me to use refcounted attribute assignment
definitions, which complicated, but probably improved memory usage.

Added link to vala bindings

Add Perl to the list of bindings.

Includes relevant Clay test

Small enhancements to remote-ls when working against local repositories

remote: add test to retrieve the advertised references from a local repository and fix related implementation

This adds APIs for querying git attributes.  In addition to
the new API in include/git2/attr.h, most of the action is in
src/attr_file.[hc] which contains utilities for dealing with
a single attributes file, and src/attr.[hc] which contains
the implementation of the APIs that merge all applicable
attributes files.

config_file: honor error

Return an error if we can't write an updated version of the config file
after config_delete.

Along with that, fix an uninitialized warning.

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

In an effort to remove duplicate code, I accidentally left
the stat structure uninitialized in this function.  This
patch restores that data gathering.

Really delete variables

Instead of just setting the value to NULL, which gives unwanted
results when asking for that variable after deleting it, delete the
variable from the list and re-write the file.

This would make us think that config variables like

    [core]
        something

is missing.

Comes with support for global events; this fixes #496.

It was not safe for git_buf_joinpath to be used with a pointer
into the buf itself because a reallocation could invalidate
the input parameter that pointed into the buffer.  This patch
makes it safe to self join, at least for the leading input to
the join, which is the common "append" case for self joins.

Also added unit tests to explicitly cover this case.

This should actually fix #511

This commit fixes #511.