Description:
------------
the casing of the mongodb functions is inconsistent with the MongoDB classes

I know php is not case sensitive when it comes comes to namespaces however comparing string does raise issues and mixing namespace casings like this does not seem like a good practice.

Test script:
---------------
<pre>
<?php

print_r(array_values(array_filter(get_declared_classes(),function($var){
    return strcasecmp(strstr($var,'\\',true) ,'mongodb') == 0;
})));

print_r(array_values(array_filter(get_defined_functions()['internal'],function($var){
    return strcasecmp(strstr($var,'\\',true) ,'mongodb') == 0;
})));
?>
</pre>

Expected result:
----------------
(the general opinion)

Array
(
    [0] => MongoDB\BSON\Binary
    [1] => MongoDB\BSON\Decimal128
  ...
    [31] => MongoDB\Driver\Exception\ExecutionTimeoutException
    [32] => MongoDB\Driver\Exception\ConnectionTimeoutException
)


Array
(
    [0] => MongoDB\BSON\fromphp
    [1] => MongoDB\BSON\tophp
    [2] => MongoDB\BSON\tojson
    [3] => MongoDB\BSON\fromjson
)

-- OR -- 

(personally I prefer camel-case/lower-case over studly-caps for namespaces (so you can see if its a namespace or class (in use statements for example)))

Array
(
    [0] => mongodb\bson\Binary
    [1] => mongodb\bson\Decimal128
  ...
    [31] => mongodb\driver\exception\ExecutionTimeoutException
    [32] => mongodb\driver\exception\ConnectionTimeoutException
)


Array
(
    [0] => mongodb\bson\fromphp
    [1] => mongodb\bson\tophp
    [2] => mongodb\bson\tojson
    [3] => mongodb\bson\fromjson
)


anyway I would expect them to match independent of the chosen casing

Actual result:
--------------

Array
(
    [0] => MongoDB\BSON\Binary
    [1] => MongoDB\BSON\Decimal128
  ...
    [31] => MongoDB\Driver\Exception\ExecutionTimeoutException
    [32] => MongoDB\Driver\Exception\ConnectionTimeoutException
)


Array
(
    [0] => mongodb\bson\fromphp
    [1] => mongodb\bson\tophp
    [2] => mongodb\bson\tojson
    [3] => mongodb\bson\fromjson
)