Since Solaris does not support some of the same flags as glibc fnmatch(),
we just use the implementation we have for Windows.

Now that it's no longer a windows-specific thing, I moved it into compat/
instead of win32/

This has the nice side effect of making test_attr_repo__staging_properly_normalizes_line_endings_according_to_gitattributes_directives() test pass again on Windows. This test started to fail after commit 674a198 was applied.

Conflicts:
	src/netops.c
	src/netops.h
	src/transports/http.c
	tests-clar/clar

This fixes all the warnings on win64 except those in deps, which
come from the regex code.

This converts blob.c, fileops.c, and all of the win32 files.
Also, various minor cleanups throughout the code.  Plus, in
testing the win32 build, I cleaned up a bunch (although not
all) of the warnings with the 64-bit build.

This converts the map validation function into a macro, tweaks
the GITERR_OS system error automatic appending, and adds a
tentative new error access API and some quick unit tests for
both the old and new error APIs.

This migrates odb.c, odb_loose.c, odb_pack.c and pack.c to
the new style of error handling.  Also got the unix and win32
versions of map.c.  There are some minor changes to other
files but no others were completely converted.

This also contains an update to filebuf so that a zeroed out
filebuf will not think that the fd (== 0) is actually open
(and inadvertently call close() on fd 0 if cleaned up).

Lastly, this was built and tested on win32 and contains a
bunch of fixes for the win32 build which was pretty broken.

This also includes droping `git_buf_lasterror` because it makes no sense
in the new system. Note that in most of the places were it has been
dropped, the code needs cleanup. I.e. GIT_ENOMEM is going away, so
instead it should return a generic `-1` and obviously not throw
anything.