Add verification of handoff heartbeat to verify_handoff test

Add testing of the handoff heartbeat change from the following pull
request: https://github.com/basho/riak_core/pull/560. Add an intercept
module for the riak_core_handoff_sender module to introduce artificial
delay on item visitation during a handoff fold. This delay along with
the changes to the verify_handoff test induces test failure when run
without the heartbeat change. The handoff_receive_timeout is exceeded,
handoff stalls, and the test eventually fails due to timeout. The test
succeeds when run with the heartbeat change.
Merge pull request #681 from basho/feature/verify-handoff-heartbeat

Add verification of handoff heartbeat to verify_handoff test
Update scripts to build more recent older versions and fix issues with Riak 1.3.x
Revert to redirecting git output to /dev/null
Add option to return exit code from rt:admin calls

Add an rt:admin/3 function that accepts a list of options as the third
parameter.  Currently the only valid option is return_exit_code. The
rtdev, rtssh, and rt_cs_dev harnesses have been updated to support
this option. If return_to_exit is specified the return from a
?HARNESS:admin call is a pair with the exit code as the first member
and the command output as the second member. Finally the
basic_command_line test has been changed to use return_for_exit to
verify the changes.
Merge pull request #682 from basho/update/bch/update-versions

Update rtdev-* Scripts and README to Reflect Latest Riak Versions; Allow build from riak_ee, too
Merge branch 'feature/riak-admin-exit-code-option'
Test for kv679 unique vnode id on a node
Merge pull request #690 from basho/bug/rdb/kv679-uid

Test for kv679 unique vnode id on a node
Add repl_fs_bench2
..
Simple function to extract aae fullsync logs
Fix variable name
Add validation function for awe full sync logs
Log scraping for validating AAE strategies
Fix div by zero when no keys changed
Improve per-partition validation
Add epl_aae_fullsync_multi_bucket.erl
Update repl_aae_fullsync_multi_bucket.erl
Fix validate_partitions for repl_aae_fullsync_multi_bucket.