Changed tests to use output= rather than capture.output. Tests after those points will now run in the 2nd repeat in verbose mode from R CMD check, which weren't before.
fread() now obeys options(datatable.verbose)
Fixed CsubsetDT() intermittent memory issue, thanks Arun for finding and reproducing.
Revert: "Check if CsubsetDT is the culprit" To confirm fails again. Then will push fix.