CSHARP-1075: Reimplement MongoDatabase RenameCollection using an operation in Core.
CSHARP-1075: Code review changes.
CSHARP-1071: Add ListIndexesOperation.
Deleted IndexExistsOperation (use ListIndexesOperation instead and examine the result to see if the index exists).
CSHARP-1079: added support to core for authMechanismPropertis
added authMechanismProperties to high level API and corrected issue with SCRAM not being used from high level api.
all connection string parsing is now handled by the core ConnectionString class. MongoUrlBuilder does not do any parsing.
fixing issues with mono build.
fixed more mono build errors.
migrated AggregateExplainOperation tests.
ported AggregateOPeration tests to Core.
ported AggregateToCollectionOperation tests.
removed function count operation tests.
ported DatabaseExistsOperations tests.
ported DistinctOperation tests.
ported ListCollectionNamesOperation tests.
ported FindOneAndDeleteOperation tests.
ported FindOneAndReplaceOperation tests.
ported FindOneAndUpdateOperationt tests.
ported FindOperation tests and beefed up related tests.