Fix build
Fix build

Sheryl removal implicite extension in overrides main properties seems to be work around to jspm build bug related to external dependencies entry map.

The list of external dependencies needed to be updated.

Fix #144
singpath/classmentors,shiquan-lim/classmentors,singpath/classmentors,shiquan-lim/classmentors,dinoboff/classmentors-1,dinoboff/classmentors-1