BSON Code inspect test for Ruby 1.8.7 unordered Hash

RUBY-548 As an engineer, I want to improve code coverage
minor: adjusting replica set size for testing, need more than one secondary
eliminate minus sign obj addr mismatch for BSON Code inspect w/ Ruby 1.8.7

RUBY-548 As an engineer, I want to improve code coverage
test that cursor operations must be on the same pool

make sure to checkout from same pool

RUBY-545 KillCursors gets sent to wrong member

RUBY-550 socket util module and refactoring
RUBY-545 ensure KillCursors gets sent to right member
use tags for cursor count tests and wait for replication on secondaries

RUBY-545 KillCursors gets sent to wrong member

RUBY-550 socket util module and refactoring
Propagate writes to 3 nodes where applicable in tests
write concern :w => 4 for test_safe_mode_w_failure

also other :w => 3 where appropriate to match 3 members

RUBY-545 KillCursors gets sent to wrong member
minor: fixing db names in tests, standardizing on MONGO_TEST_DB
merging in upstream changes