LU-9795 tests: exclude several tests which conflict with SSK

When SSK is activated by setting SHARED_KEY to true,
some tests in various suites fail, often because components
are manually halted or failed.
This patch excludes these tests under SSK and makes minor changes
for SSK compatibility.

Also reconnect client-to-OST connections if they became idle.
This new idle ability is brought by patch
https://review.whamcloud.com/16682 and it prevents idle OSCs from
taking into account new GSS flavor.

Change-Id: I998ae9bf1998f206914ff425e1f6e27741443e9c
Test-Parameters: testlist=sanity-gss envdefinitions=ONLY=1,SHARED_KEY=true
Signed-off-by: Chris Hanna <hannac@iu.edu>
Signed-off-by: Sebastien Buisson <sbuisson@ddn.com>
Reviewed-on: https://review.whamcloud.com/28662
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: James Simmons <uja.ornl@yahoo.com>
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>