Rx: Build rxperf test application on Windows

Rx: Build rxperf test application on Windows

rxperf made assumptions that it was built against LWP, used buffer
sizes for read/write that were too small, made use of non-portable
types, and set signal handlers that are unsupported.

Change-Id: I55515cac0f441116df7fd0aaf100fb3ae99b220f
Reviewed-on: http://gerrit.openafs.org/2773
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Derrick Brashear <shadow@dementia.org>
Tested-by: Derrick Brashear <shadow@dementia.org>
(cherry picked from commit 449976acd54ff46fd6cdb9a6e12acf3789665bcf)
Reviewed-on: http://gerrit.openafs.org/2805