Use PapiSocketProvider for most PAPI calls

Ticket: CSIT-1541
Ticket: VPP-1722
Ticket: CSIT-1546

+ Increase timeout to hide x520 slownes of show hardware detail.
- Install sshpass and update ssh client in virl bootstrap.
 + Added TODOs to remove when CSIT-1546 is fixed.
+ Enable default socksvr on any startup conf.
+ Improve OptionString init and repr.
- The non-socket executor still kept for stats.
 + Remove everything unrelated to stats from non-socket executor.
- Remove some debug-loooking calls to avoid failures.
  TODO: Introduce proper parsing to the affected keywords.
+ Reduce logging from PAPI code to level INFO.
 - Needs https://gerrit.fd.io/r/20660 to fully work.
+ Change default values for LocalExecution.run()
 + Return code check enabled by default.
   Code is more readable when rc!=0 is allowed explicitly,
   and the test code will now detect unexpected failures.
 + Logging disabled by default.
   Output XML is large already. Important logging can be enabled explicitly.
+ Restore alphabetical order in common.sh functions.

Change-Id: I05882cb6b620ad14638f7404b5ad38c7a5de9e6c
Signed-off-by: Vratko Polak <vrpolak@cisco.com>