Remove autogenerated files from the repository

Add an autogen.sh to regenerate them.

.gitignore

@@ -5,14 +5,25 @@
 .dirstamp
 *.la
 Makefile
-config.log
-config.status
+Makefile.in
+aclocal.m4
+compile
+config.*
+configure
+depcomp
 *~
 fficonfig.h
 include/ffi.h
 include/ffitarget.h
+install-sh
 libffi.pc
 libtool
+libtool-ldflags
+ltmain.sh
+m4/libtool.m4
+m4/lt*.m4
+mdate-sh
+missing
 stamp-h1
 libffi*gz
 autom4te.cache