Fix test_id_shuffling PYTHON-441

SON equality is now order sensitive.
Work around Jython dict equality issue PYTHON-441

See http://bugs.jython.org/issue1728
Clarify max_pool_size docs and update pooling FAQ
Help people avoid common pitfall: not converting from string to ObjectId
Rewrite Gevent example, most people shouldn't set use_greenlets but instead should just patch_all() PYTHON-435
float('inf') isn't available everywhere, use 1e100000 instead
Clarify order of imports in Gevent example
improving warning message for URI
Merge pull request #147 from mulka/master

improving warning message for URI
Update URI warning in MongoReplicaSetClient.
Fix issue with empty queries against $cmd.
float('inf') isn't available everywhere, use 1e9 instead
BUMP 2.4
Version -> +
Test validation of Read Preference options PYTHON-444
Properly handle secondaryAcceptableLatencyMS PYTHON-444
Missing import in connection.py and replica_set_connection.py
Fix $cmd queries with $readPreference PYTHON-446
More thoroughly test the behavior of slave_okay and sending $readPreference to mongos PYTHON-448
Fix test_ha.py's imports for MongoClient