Revert "clean up module implementation by removing conditional exports"
Revert "clean up module implementation by removing conditional exports"

This reverts commit de34cc3e55cb4580220a26e0157a61db9ae4f8c4.

The commit negated the intention of commit 642323e - "Return early if no
`window` object (eg. Node.js)".

adamgruber/interact.js,taye/interact.js,Endika/interact.js,taye/interact.js,marian-r/interact.js,taye/interact.js,marian-r/interact.js,adamgruber/interact.js,bios21/interact.js,Endika/interact.js,bios21/interact.js