xbmc: update to xbmc-acfe70f

Signed-off-by: Stephan Raue <stephan@openelec.tv>
libmicrohttpd: only build needed library, dont build docs and examples, this should fix #1711

Signed-off-by: Stephan Raue <stephan@openelec.tv>
Merge branch 'master' of github.com:OpenELEC/OpenELEC.tv