Revert "nsq_to_file: don't open multiple GZIP streams"
Revert "nsq_to_file: don't open multiple GZIP streams"

This reverts commit 5ea1012443c194b62a10b05a80d7d897f35f77e8.

also some further tweaks due to FileLogger refactor

rpau/nsq,jehiah/nsq,ploxiln/nsq,jehiah/nsq,ploxiln/nsq,nsqio/nsq,bitly/nsq,rpau/nsq,bitly/nsq,mreiferson/nsq,bitly/nsq,ploxiln/nsq,mreiferson/nsq,jehiah/nsq,mreiferson/nsq,bitly/nsq,nsqio/nsq,bitly/nsq,rpau/nsq,mreiferson/nsq,nsqio/nsq,ploxiln/nsq,nsqio/nsq,rpau/nsq,rpau/nsq,nsqio/nsq,ploxiln/nsq,mreiferson/nsq,jehiah/nsq,jehiah/nsq