There is not libbb include path, dropped

Signed-off-by: Stefano Babic <sbabic@denx.de>
Drop compiler defines not used anymore.

Moving to LUA package, it is not necessary anymore
to set -D options to compile LUA.

Signed-off-by: Stefano Babic <sbabic@denx.de>
Print build date at the startup

Signed-off-by: Stefano Babic <sbabic@denx.de>