build: Add gitattribute file to build-aux

The command: `make check-tabs` fails on Windows due to line ending conversions
caused by the following setting: `git config --global core.autocrlf true`
(the whitelist `build-aux/initial-tab-whitelist` becomes a blacklist)

This patch adds a .gittatribute file to build-aux to force LF endings
on Windows.

Signed-off-by: Alin Gabriel Serdean <[email protected]>
Co-authored-by: Aaron Conole <[email protected]>
Signed-off-by: Aaron Conole <[email protected]>
Acked-by: Ben Pfaff <[email protected]>

Author: aserdean

.gitignore

@@ -31,7 +31,6 @@
 .libs
 .tmp_versions
 .vagrant
-.gitattributes
 /Makefile
 /Makefile.in
 /aclocal.m4

Makefile.am

@@ -199,6 +199,7 @@ dist-hook-git: distfiles
 	  (cat distfiles; sed 's|^|datapath/|' datapath/distfiles) | \
 	    LC_ALL=C sort -u > all-distfiles; \
 	  (cd $(srcdir) && git ls-files) | grep -v '\.gitignore$$' | \
+	    grep -v '\.gitattributes$$' | \
 	    LC_ALL=C sort -u > all-gitfiles; \
 	  LC_ALL=C comm -1 -3 all-distfiles all-gitfiles > missing-distfiles; \
 	  if test -s missing-distfiles; then \

build-aux/.gitattributes

@@ -0,0 +1 @@
+* text eol=lf