fix(webpack): explicit angular2 alias
fix(webpack): explicit angular2 alias

When using 'npm link' for development against a local ionic, the ionic
source files will reference angular2 in their own node_modules
directory, not the one in the conference app's node_modules, causing
angular2 to be included twice as well as some hard to track down errors.

Beslinda/catalogIonicApp,nReality/AgileAfricaConf-app,francarmona/ionice-contryside-events-app,francarmona/ionice-contryside-events-app,ericel/weytindey,nReality/AgileAfricaConf-app,nReality/SUGSA-ScrumGathering-App2016,ericel/weytindey,nReality/SUGSA-ScrumGathering-App2016,nReality/AgileAfricaConf-app,sinholic/aero-flyer,subsolo/ITHC,kumarnavinrai/finalmcu,laodice/ionic-conference-app-session2,minhlong/NamHoa-Ionic,nReality/SUGSA-ScrumGathering-App2016,kumarnavinrai/finalmcu,abdolmajidazad/neveshtak,laodice/ionic-conference-app-session2,nReality/SUGSA-ScrumGathering-App2016,subsolo/ITHC,kumarnavinrai/finalmcu,TobiasSchaeuble/HMAD,pierrecabriere/Greencharge,tommy-boy/AMZNDEALS,Beslinda/catalogIonicApp,francarmona/ionice-contryside-events-app,nReality/AgileAfricaConf-app,sinholic/aero-flyer,minhlong/NamHoa-Ionic,abdolmajidazad/neveshtak,pierrecabriere/Greencharge,fmsouza/mangiare,nReality/SUGSA-ScrumGathering-App2016,driftyco/ionic-conference-app,tommy-boy/AMZNDEALS,sinholic/aero-flyer,pierrecabriere/Greencharge,nReality/SUGSA-ScrumGathering-App2016,fmsouza/mangiare,nReality/AgileAfricaConf-app,fmsouza/mangiare,TobiasSchaeuble/HMAD,driftyco/ionic-conference-app,TobiasSchaeuble/HMAD,driftyco/ionic-conference-app,minhlong/NamHoa-Ionic,ericel/weytindey,subsolo/ITHC,fmsouza/mangiare,ziggyJ/ionic-conference-app,nReality/SUGSA-ScrumGathering-App2016,nReality/AgileAfricaConf-app,abdolmajidazad/neveshtak,tommy-boy/AMZNDEALS,ziggyJ/ionic-conference-app,nReality/AgileAfricaConf-app,Beslinda/catalogIonicApp,laodice/ionic-conference-app-session2