Revert "Rename the .to_plist method in cfpropertylist to .to_cfplist"

This reverts commit f579d2acc7d74f5d0dc41bee583cc9625ba6e04a.
Working in wrong branch
Revert "Use Plist::Emit.dump() directly instead of calling .to_plist"

This reverts commit 79e79ef91d6b2048e18b6179557a616f45a9f603.
Working in wrong branch.