This adds inheritance of the Database's type map option, which should have been added in 330e1e30.

Property access, which was already enabled on unserialization, allows code to work with the model as it would the driver's default stdClass

This should be considered an internal interface until driver interfaces are available and we can use ServerInterface (see: PHPC-378).

 Please enter a commit message to explain why this merge is necessary,

empty() is inconsistent for checking if the document is empty (i.e. empty([]) != empty(new stdClass)). Simply check that the option has been set in order to include it in the command.

This refactors the existing Database method to use an Operation class.

Parsing the "readconcernlevel" URI option depends on PHPC-523, so we'll skip those tests for now.