SERVER-10641 Stable floating-point comparison when validating min/maxDistance

Signed-off-by: Matt Kangas <matt.kangas@mongodb.com>
SERVER-10362 actually sleep when writers yield
SERVER-10641 fix compile for Windows
SERVER-8378 make bg index test more reliable

I needed to comment out the 'remove' part because the current deleteObject code gets bullied if
another writer is taking a write lock for long quanta, and it never makes forward progress.
Hopefully the new query planner code, which uses a better yielding strategy, will allow
this to be turned back on soon.
SERVER-10655 aggregation_auth : mongos_slaveok.js failing

Improve test.
SERVER-10655 aggregation_auth : mongos_slaveok.js failing

Setup the connection pool hooks to properly authenticate connections when aggregate command has the fromRouter parameter.