The grep from BusyBox is not complete, not support "-e"

for Attitude Adjustment only

echo "src-git addon https://github.com/sonnyyu/addon.git" >>feeds.conf.default
./scripts/feeds update addon
./scripts/feeds install -p addon grep
make menuconfig
make package/feeds/addon/grep/clean V=s
make package/feeds/addon/grep/compile V=s