dancer2: all packages

TT: PERL_TEMPLATE_TOOLKIT_CONF_OPT = "TT_XS_ENABLE=n"
network interface eth0
defconfig
demo

set BR2_ROOTFS_OVERLAY with $(BR2_EXTERNAL)/overlay/
dancer2 skeleton

$ dancer2 gen -a MyWeb::App
Dancer2 as service
BR demo
add DateTime
add GDGraph
add Chart-Plot-Tagged
add ntp in defconfig
update plot