Document MongoCursor::maxTimeMS()

https://jira.mongodb.org/browse/PHP-1023


git-svn-id: https://svn.php.net/repository/phpdoc/en/trunk@333264 c90b9560-bf6c-de11-be94-00142212c4b1
Document MongoDB maxTimeMS command/query option

Also expanded upon aggregate command options.

https://jira.mongodb.org/browse/PHP-1023


git-svn-id: https://svn.php.net/repository/phpdoc/en/trunk@333265 c90b9560-bf6c-de11-be94-00142212c4b1