Re-enable compactions during writes
Re-enable compactions during writes

A cold shard that suddenly receives a lot of writes could get a very
big cache that takes a long time to snapshot or causes the cache
max memory limit to be hit more quickly.  This re-enables the compactions
if necessary during writes so we don't have to wait for the shard monitor
goroutine to re-enable them.

benbjohnson/influxdb,vladlopes/influxdb,li-ang/influxdb,mark-rushakoff/influxdb,nooproblem/influxdb,li-ang/influxdb,vladlopes/influxdb,benbjohnson/influxdb,linearb/influxdb,nooproblem/influxdb,nooproblem/influxdb,linearb/influxdb,influxdata/influxdb,vladlopes/influxdb,mark-rushakoff/influxdb,mark-rushakoff/influxdb,influxdb/influxdb,linearb/influxdb,influxdb/influxdb,nooproblem/influxdb,mark-rushakoff/influxdb,influxdb/influxdb,linearb/influxdb,nooproblem/influxdb,vladlopes/influxdb,benbjohnson/influxdb,linearb/influxdb,benbjohnson/influxdb,mark-rushakoff/influxdb,influxdb/influxdb,influxdata/influxdb,influxdb/influxdb,influxdb/influxdb,mark-rushakoff/influxdb