--begin package parsing refactoring--
(checkpoint -- going a different direction)
grab dependency list from package by calling on_xxx at load time.
don't use it yet
initFromAppDir generates new-style package info
remove registered_extensions from on_use API
Include 'meteor' in new-style dependency lists
use new-style package info for exports
Move get_source_handler from pbi to package
store exports on package, not pbi
compute load order only once and store on Bundle
refactor determineLoadOrder interface
Assemble imports using package info, not pbi. Add missing imports to account-base.
get all package dependency info from Package objects rather than pbis
Separate pass for npm modules
Don't call package.js code at bundle time! Also, add some missing dependencies
Get rid of pbi api. Fold remaining functionality into bundler.
WIP
constrain use to take exactly one where at a time
fold use() into determineLoadOrder()
move dependencies out of pbi. also delete 'bundle' field.
keep pbi list in only one place: pbisByLoadOrder
each pbi now only handles one where