add .gitignore file for autoconf-generated stuff
diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..8c0f25f
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,15 @@
+Makefile.in
+aclocal.m4
+autom4te.cache
+config.guess
+config.h.in~
+config.sub
+configure
+depcomp
+install-sh
+missing
+doc/Makefile.in
+ggsn/Makefile.in
+gtp/Makefile.in
+sgsnemu/Makefile.in
+*.swp