regs #147 - refactored gcs closing to be able to do emergency close from gcs_recv_thread
refs #147 fixed assertions
refs #102 reserved 8 byte version field from EVS message, initial protocol upgrade for EVS and PC
refs #102 - PC protocol version tied to EVS, unit tests
Revert "refs #153 ported fix from gh71 branch"

This reverts commit b5c3115a00f8dcdd3c071dd9720e0a852d24081b.
refs #153 protect connection appropriately also on get_stats, other backend close related fixes
Merge pull request #150 from codership/gh147

regs #147 - refactored gcs closing to be able to do emergency close from...
Merge pull request #154 from codership/gh102

refs #102 - Preparing for gcomm protocol version upgrades
Merge branch 'gh153' into 3.x
Merge galera-3.x upto 2ece146125b1362a9c5227e62a79d5f226eb64cb