Fixed formatting of diff-internals.md

Indentation for lists was not working correctly.

Make tests pass if XDG config exists

Alternative fix for cross protocol redirects

The subtransport path was relying on pointing to data owned by
the remote which meant that after a redirect, the updated path
was getting lost for future requests.  This updates the http
transport to strdup the path and maintain its own lifetime.

This also pulls responsibility for parsing the URL back into the
http transport and isolates the functions that parse and free that
connection data so that they can be reused between the initial
parsing and the redirect parsing.

Ignore files that disappear while iterating

On occasion, files can disappear while we're iterating the
filesystem, between calls to readdir and stat.  Let's pretend
those didn't exist in the first place.

Various warning cleanup and minor fixes

Minimize regex usage

The git_buf_text_gather_stats call returns a boolean indicating if
the file looks like binary data.  That shouldn't be an error; it
should be used to skip CRLF processing though.

'del' instead of 'delete' for the poor C++ users

This replaces some git_buf_printf calls with simple calls to
git_buf_put instead.  Also, it fixes a missing va_end inside
the git_buf_vprintf implementation.

The attempt to "clean up warnings" seems to have introduced some
new warnings on compliant compilers.  This fixes those in a way
that I suspect will also be okay for the non-compliant compilers.

Also this fixes what appears to be an extra semicolon in the
repo initialization template dir handling (and as part of that
fix, handles the case where an error occurs correctly).

In revwalk, we are doing a very simple check to see if a string
contains wildcard characters, so a full regular expression match
is not needed.

In remote listing, now that we have git_config_foreach_match with
full regular expression matching, we can take advantage of that
and eliminate the regex here, replacing it with much simpler string
manipulation.

Fix typo in documentation

Make it pair up with the one for commits. This fixes #1691.

Fix warning

OSX 10.8 + Valgrind

Make init.templatedir work

indexer: check the packfile trailer

The packfile trailer gets sent over and we should check whether it's
correct as part of our sanity checks of the packfile.

Configurable template dir for Win32

Alternative proposal for filter API

This updates clar to the version without cl_assert_equal_sz and
then adds a new version of that macro the clar_libgit2.h.  The new
version works around a strange issue that seemed to be arising on
release builds with VS 10 64-bit builds.

This contains a few bug fixes and some header and API cleanups.

The main API change is that filters should now use GIT_PASSTHROUGH
to indicate that they wish to skip processing a file instead of
GIT_ENOTFOUND.

The bug fixes include a possible out-of-range buffer access in
the ident filter, a filter ordering problem I introduced into the
custom filter tests on Windows, and a filter buf NUL termination
issue that was coming up on Linux.