Make AMD module id's optional
Make module id's for AMD body in UMD optional as well
Improve performance
Added an interop commonjs loader.
Allow module transformers to be directly passed into opts.
Merge pull request #192 from Naddiseo/function-modules

Allow module transformers to be directly passed into opts.
Merge pull request #191 from Naddiseo/commonjs-interop

Added an interop commonjs loader.
more regenerator spring cleaning
add assertion checks into types
add util.arrayify and util.regexify
use regexify and arrayify in register options
expose util as _util
arrayify whitelist and blacklist, inherit moduleRoot from sourceRoot and vice versa
check for existence of node before checking it in let scoping
clean up common-interop module formatter
use commonInterop module formatter in 6to5/register
generator: add existence check to printJoin
add interop-require declaration
publish acorn-6to5 as an npm package - fixes #187
remove unused variable in generators/meta