Compatibility with ext-mongodb 0.6

As of PHPC-255, we cannot rewind a Cursor. PHPLIB-81 will ultimately change this by caching results; however, there is also no need to assert the iterator count here, since we're asserting the name during iteration (two CollectionInfo results would not share the same name).

Per PHPLIB-93, these classes should always have an ID, regardless of whether the driver needed to generate one.

PHPLIB-89: String getters for Database and Collection classes

This should avoid hanging test builds if mongod fails to start.

We need to account for differing service names between 2.4 and 2.6+.

nModified is not provided for legacy write ops, so we should not check for it. Once PHPC-278 is implemented, we can change these assertions to check for null exactly.

This adds intelligent detection for the useCursor option's default value. Additionally, server 2.4 does not support any of the aggregate command options of newer servers, so we must not specify default values.

The array_map() conversion for inline aggregation results is not ideal, but we can revisit that in PHPLIB-100.

Earlier server versions incorrectly return an empty document instead of null. Thankfully, we can detect this edge case given the command result and input options.

Older servers may return floats.

This was inadvertently removed in 495e46d4.