Git: add export-ignore for git config file

* Prevents release archives produced from git to contain
  git related files.
diff --git a/.gitattributes b/.gitattributes
index 1a1929c..a142985 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -1,7 +1,9 @@
-*.sh eol=lf
-*.ac eol=lf
-*.am eol=lf
-*.dsw eol=crlf
-*.dsp eol=crlf whitespace=space-before-tab
-*.sln eol=crlf
-*.vcxproj* eol=crlf
+*.sh            eol=lf
+*.ac            eol=lf
+*.am            eol=lf
+*.dsw           eol=crlf
+*.dsp           eol=crlf whitespace=space-before-tab
+*.sln           eol=crlf
+*.vcxproj*      eol=crlf
+.gitattributes  export-ignore
+.gitignore      export-ignore