Added keep_dirs and conf_files vars for templates.

These will be written in pkg metadata props file as well. For now
they don't change any behaviour, will be used in binary packages.

Convert some pkgs to use them.

--HG--
extra : convert_revision : d04f681cf80dc97ceb9e50370d5a8c0d7b52687c

templates/openssl.tmpl

@@ -19,6 +19,8 @@ long_desc="
 
 # Does not build with -j.
 disable_parallel_build=yes
+keep_dirs="/etc/ssl"
+conf_files="/etc/ssl/openssl.cnf"
 build_depends="perl-5.10.0 zlib-1.2.3"
 run_depends="glibc-2.8 zlib-1.2.3"