Only generate .provided file when actually building a rootfs.
Add curl temporary at build time.
Change upstream default to http, add proper forwarded headers.
Handle https forwarding to php when using proxy. Add pecl-{memcache,apcu,redis}.
Mount given image config dir.
Bumped date to 20141016.
Add update cmd to build.sh, sets DATE in build.sh to latest stage3 build date.