- re-enable upgrade and restrict it to signle packages, fix usage text
- only read package descriptions if they're actually needed (almost never),
saves even more space when parsing package lists
- refresh patches
git-svn-id: svn://svn.openwrt.org/openwrt/trunk@18120 3c298f89-4303-0410-b956-a3cf2f4a3e73
