Revert "More robust onexit". Accidental push to master.
Revert "More robust onexit". Accidental push to master.

This reverts commit 228e229fb00d94a1192e0ce6dff4c1e83657fa34.

Rdatatable/data.table,Rdatatable/data.table,vlulla/data.table,Rdatatable/data.table,jangorecki/data.table,jangorecki/data.table,Rdatatable/data.table,vlulla/data.table,jangorecki/data.table,jangorecki/data.table,vlulla/data.table,vlulla/data.table