liblzma: Add .gitattributes to ignore whitespace checks

Tell Git not to check whitespace in third-party code.
liblzma 5.0.5-gb69900ed (reduced)

Extract upstream liblzma using the following shell code.

url=http://git.tukaani.org/xz.git &&
v=5.0.5 &&
r=b69900ed &&
paths="
  COPYING
  src/common/common_w32res.rc
  src/common/sysdefs.h
  src/common/tuklib_integer.h
  src/liblzma
" &&
mkdir liblzma-$v-g$r-reduced &&
git clone $url liblzma-git &&
date=$(cd liblzma-git && git log -n 1 --format='%cd' $r) &&
(cd liblzma-git && git archive --format=tar $r -- $paths) |
(cd liblzma-$v-g$r-reduced && tar xv &&
 mv src/* . && rmdir src) &&
echo "g$r date: $date"
Merge branch 'liblzma-upstream' into add-liblzma
CMake Nightly Date Stamp
Merge topic 'fix-complex-test-policies'

fb95f820 Tests: Set policies in 'complex' tests
Merge topic 'fix_sanitizer_test_to_work_with_sanitizer'

f7d62cac Fix leak and address sanitizer tests to be able to run with real tools.
Merge topic 'refactor-generator-startup'

f5c0efdb cmGlobalGenerator: Create a non-virtual 'DoGenerate' method
Merge topic 'refactor-makerule-path-conversion'

848fab95 cmGlobalVisualStudio7Generator: Remove unused variable
85cea8a7 cmDepends: Refactor object file path conversion
e7ee892b cmLocalGenerator: Fix AddBuildTargetRule object file path conversion
9f92a78b cmLocalGenerator: Rename 'MAKEFILE' to 'MAKERULE'
Merge branch 'master' into next
liblzma: Add README-CMake.txt

Describe how to update liblzma from upstream.
liblzma: Remove unused Makefile.* files

We will provide our own CMake-based build system.
liblzma: Add CMake build system

Modify sources just enough to build without the full xz common
directory.
liblzma: Port from C99 to C89/90
liblzma: Port to VS 6
CMake: Enable use of liblzma in libarchive (#14504)

Build liblzma as part of CMake or find one on the system.  Modify our
port of libarchive to use the liblzma configured for use with CMake.
Merge topic 'add-liblzma' into next

2e45b40f CMake: Enable use of liblzma in libarchive (#14504)
7ee85157 liblzma: Port to VS 6
0430e5dd liblzma: Port from C99 to C89/90
b2a07ca4 liblzma: Add CMake build system
d44ad161 liblzma: Remove unused Makefile.* files
a53caea3 liblzma: Add README-CMake.txt
133d42fe Merge branch 'liblzma-upstream' into add-liblzma
c289e634 liblzma 5.0.5-gb69900ed (reduced)
8510533f liblzma: Add .gitattributes to ignore whitespace checks
Fix memory leaks in extract tar.
Merge topic 'fix_tar_leaks' into next

57a2df22 Fix memory leaks in extract tar.
liblzma: Port to VS 7.0

Use the same UINT64_C suffix as that for VS 6.
Merge topic 'add-liblzma' into next

31192973 liblzma: Port to VS 7.0