Avoid unnecessarily long node_modules paths for plugin isopacks.
Avoid unnecessarily long node_modules paths for plugin isopacks.

Long paths pose real problems on Windows, and may have exacerbatd the
consequences of #6609.

nuvipannu/meteor,DAB0mB/meteor,chasertech/meteor,lorensr/meteor,chasertech/meteor,lorensr/meteor,mjmasn/meteor,Hansoft/meteor,mjmasn/meteor,nuvipannu/meteor,chasertech/meteor,4commerce-technologies-AG/meteor,lorensr/meteor,nuvipannu/meteor,lorensr/meteor,mjmasn/meteor,nuvipannu/meteor,jdivy/meteor,nuvipannu/meteor,mjmasn/meteor,jdivy/meteor,lorensr/meteor,lorensr/meteor,Hansoft/meteor,chasertech/meteor,DAB0mB/meteor,DAB0mB/meteor,DAB0mB/meteor,mjmasn/meteor,chasertech/meteor,4commerce-technologies-AG/meteor,4commerce-technologies-AG/meteor,jdivy/meteor,Hansoft/meteor,jdivy/meteor,chasertech/meteor,4commerce-technologies-AG/meteor,4commerce-technologies-AG/meteor,Hansoft/meteor,chasertech/meteor,Hansoft/meteor,mjmasn/meteor,4commerce-technologies-AG/meteor,Hansoft/meteor,nuvipannu/meteor,DAB0mB/meteor,jdivy/meteor,Hansoft/meteor,mjmasn/meteor,jdivy/meteor,DAB0mB/meteor,4commerce-technologies-AG/meteor,jdivy/meteor,lorensr/meteor,DAB0mB/meteor,nuvipannu/meteor