Refs #106: remove ist_sst_ and unnecessary gcs_.join
Refs #106: remove if condition. call gcs_.join anyway when sst is done
Refs #106: add join flags to ist sender which means join back to cluster when it exits. it is introduced because sometimes sst_sent may not be called.
Refs #90: perform refactor on check_traces
Refs #90: add comparison when regular view id is the same but previous trans view id is not the same
Refs #90: if reg view is same but next trans view has different members, then members should be disjoint. remove some redudant comparison and use std::inserter to avoid fixed size output container
Merge pull request #134 from codership/gh90

Gh90
Updates to admin guide.  Fixed bad link on Reference.
Documentation moved to https://github.com/codership/documentation
refs #139 - made PC send errors to match gcs core counterparts to
            have appropriate error codes from backend in gcs
            core sending.
Merge pull request #140 from codership/gh139

refs #139 - made PC send errors to match gcs core counterparts to  have appropriate error codes from backend in gcs core sending.
Refs #106: call gcs_join right after IST. otherwise node could serve IST or SST for only one node, which is not we expect
Refs #106: remove duplicate condition
Merge pull request #146 from codership/gh106

Gh106
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
refs #153 ported fix from gh71 branch
Bumped version to 3.8.