use R 3.0.0 compatible code in tests, closes #2292 (#2293)
use R 3.0.0 compatible code in tests, closes #2292 (#2293)


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