with_max_wire_version test framework for wire version feature testing

RUBY-676
insert partial batch up to serialization error - logic fix for ordered semantics

RUBY-676
refactor bulk execute into operation and command writers

legacy command emulation must use single write operations, including inserts
unify bulk insert ops via {:d => document}

RUBY-676
bulk execute documentation with performance warning for legacy servers

RUBY-676
bulk execute merged result with tallying, index mapping, top-level processing

RUBY-676