refs #100 Remember highest seen view seqno to make sure that
          install view id always increases when install message
          is regenerated. Unit test.
refs #100 Remember highest seen view seqno

to make sure that install view id always increases when install
message is regenerated. Unit test.

Merged from 3.x, added rst_view to evs::Proto constructor to
make unit test work.
Port fixes from 3.x branch
Merge galera-2.x upto 6912f625947e611eff614120d1299b80b02d3703