Merge pull request #3054 from blocktrron/flexible-feature-packages

Makefile

contrib/ci/minimal-site/image-customization.lua

contrib/ci/olsr-site/image-customization.lua

contrib/ci/olsr-site/site.mk

docs/dev/packages.rst

docs/features/multidomain.rst

docs/features/private-wlan.rst

docs/features/vpn.rst

docs/multidomain-site-example/image-customization.lua

docs/multidomain-site-example/site.mk

docs/package/gluon-ebtables-limit-arp.rst

docs/site-example/image-customization.lua

docs/site-example/site.mk

docs/user/site.rst

package/features

scripts/image_customization_lib.lua

scripts/target_config_lib.lua

scripts/target_lib.lua