LU-11128 ptlrpc: add debugging for idle connections

Add a "debug" parameter for the idle client disconnection so that
it can log disconnect/reconnect events to the console.

Print the idle time in the "import" file.

Enable the connection debugging for all test runs.

Signed-off-by: Andreas Dilger <adilger@whamcloud.com>
Change-Id: I47a4f73542fb4864e4f35275ecfe8907493ebbe5
Reviewed-on: https://review.whamcloud.com/33168
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Alex Zhuravlev <bzzz@whamcloud.com>
Reviewed-by: Nathaniel Clark <nclark@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>