Add note about license headers (fixes #227)
Add note about license headers (fixes #227)

Serious-Rage/poligomy,lordoftheflies/mlm-portal,gick/mobile-polymer-starter-2,Jelle-imitto/tools-polymer,stephenzsy/charon-frontend,andrefuller/PolymerTrailerViewer,1001genomes/admixture-map,JnJSW/dttdata,Ex-ante-Labs/shopper.ninja,alexpaluzzi/polymer-starter-kit,plusCubed/pluscubed-site,robdodson/polymer-starter-kit,stephenzsy/charon-frontend,Serious-Rage/poligomy,Ex-ante-Labs/shopper.ninja,Ex-ante-Labs/pivot-ahead,stefanoantonel/brainpower,robdodson/polymer-starter-kit,Negashev/negash.ru,RoyKoh/Project-3,felixzapata/polymer-starter-kit,StartPolymer/polymer-starter-kit,gick/mobile-polymer-starter-2,plusCubed/pluscubed-site,jdavidagudelo/polymerstarter,gick/reveries-project,SB-Technology-Holdings-International/Water,mtusk/polymer-starter-kit,flaiker/polymer-starter-kit,FaellCarvalho/Geo-Location,jdavidagudelo/polymerstarter,JnJSW/dttdata,StartPolymer/polymer-starter-kit-plus,proplanr/polymer-starter-kit,SB-Technology-Holdings-International/Water,SB-Technology-Holdings-International/Water,lordoftheflies/mlm-portal,Jelle-imitto/tools-polymer,RoyKoh/Project-3,JnJSW/dttdata,semafloor/semafloor-test-alpha,felixzapata/polymer-starter-kit,gick/reveries-project,trendystore/store,semafloor/semafloor-test-alpha,stefanoantonel/brainpower,anthonybrown/polymer-starter-kit,Jelle-imitto/tools-polymer,Ex-ante-Labs/pivot-ahead,natabbotts/blogs.org.uk,SB-Technology-Holdings-International/WateringWebClient,tecla5/site,gertcuykens/polymer-starter-kit,victorgb6/id-questionary,proplanr/polymer-starter-kit,SB-Technology-Holdings-International/WateringWebClient,proplanr/polymer-starter-kit,SB-Technology-Holdings-International/WateringWebClient,gertcuykens/polymer-starter-kit,ragingwind/polymer-starter-kit,SB-Technology-Holdings-International/WateringWebClient,trendystore/store,Jelle-imitto/tools-polymer,FaellCarvalho/Geo-Location,RoyKoh/Project-3,anthonybrown/polymer-starter-kit,stefanoantonel/ecofit,mtusk/polymer-starter-kit,trendystore/store,SB-Technology-Holdings-International/Water,Sykkro/penny-web,ragingwind/polymer-starter-kit,semafloor/semafloor-test-alpha,markovuksanovic/polymer-starter-kit,Sykkro/penny-web,lordoftheflies/mlm-portal,alexpaluzzi/polymer-starter-kit,LM450N/polymer-starter-kit,natabbotts/blogs.org.uk,gick/reveries-project,andrefuller/PolymerTrailerViewer,grebett/polymer-starter-kit,markovuksanovic/polymer-starter-kit,gianluka79/First,Negashev/negash.ru,victorgb6/id-questionary,grebett/polymer-starter-kit,flaiker/polymer-starter-kit,victorgb6/id-questionary,abdonrd/polymer-starter-kit,LM450N/polymer-starter-kit,grebett/polymer-starter-kit,gertcuykens/polymer-starter-kit,klarkc/polymer-loopback-starter-kit,felixzapata/polymer-starter-kit,michaetto/f16,gianluka79/First,stefanoantonel/ecofit,StartPolymer/polymer-starter-kit,1001genomes/admixture-map,StartPolymer/polymer-starter-kit-plus,SB-Technology-Holdings-International/Water,andrefuller/PolymerTrailerViewer,gianluka79/First,stephenzsy/charon-frontend,stefanoantonel/ecofit,klarkc/polymer-loopback-starter-kit,michaetto/f16,alexpaluzzi/polymer-starter-kit,ragingwind/polymer-starter-kit,LM450N/polymer-starter-kit,michaetto/f16,markovuksanovic/polymer-starter-kit,Negashev/negash.ru,Serious-Rage/poligomy,klarkc/polymer-loopback-starter-kit,abdonrd/polymer-starter-kit,gick/mobile-polymer-starter-2,Jelle-imitto/tools-polymer,FaellCarvalho/Geo-Location,tecla5/site,Sykkro/penny-web