Simon Marlow authored Apr 11, 2012 and pcapriotti committed Apr 12, 2012

Firstly, we were rounding up too much, such that the smallest delay
was 20ms.  Secondly, there is no need to use millisecond resolution on
a 64-bit machine where we have room in the TSO to use the normal
nanosecond resolution that we use elsewhere in the RTS.

MERGED from commit 9d26519c