Documentation fixes

[corpsee]

Documentation fixes

[lindelius]

@corpsee Line 102 (after changes) in src/Operation/CreateIndexes.php should actually read:

* @param Server $server

[corpsee]

@lindelius You are right, thx

[jmikola]

I realized while reviewing that this function's return value is never used. I've removed it entirely in #188.

[jmikola]

Thanks for the contribution. I've selected parts of this PR and merged them to v1.0 in bc64127.

To explain why I've omitted other parts of the PR:

• The doc blocks for private member variables aren't used for generating API documentation. Since these members are internal, I'd prefer to just name them sensibly and keep them self-documenting. In the cases of private static members, those are effectively internal constants whose value is immediately assigned (I don't see the value of prefixing them with /** @var array */ or /** @var int */).
• I am currently working through refactoring the GridFS component, so its code is in flux. I will be taking a final pass at the documentation for its public API once that refactoring is complete.