Fixed PHP-629: Missing support for passing the username/password in the $options array

If we don't set a database we don't notice this is supposed to be an
authenticated connections.
Since `ismaster` commands don't require authentication we can get an
valid connection back, but since its not authenticated it'll fail on
first query/command.
Expand comment a little to explain that it is safe to set the "admin" value here already.
Merged pull request #243
Fixed PHP-631: One replica set, but two different db/user/passwords

We didn't actually filtered anything at all by credentials.
That was dropped in 496d77b907885f2f718d2e23530e0c7ff7677460 and
replaced with a replicaset name check, but missed matching the
credentials. We now check the credentials after the initial
connection filtering.
Improve existency and free checks.

We should reset the parameters to NULL at every iteration of the loop as free()
does not set the ptr to NULL. This might technically not be needed as the hash
break up function sets things to NULL, but better safe than sorry.  The ->db
argument should also be checked for as, we do just strcmp() it later.
Improve log messages a bit.

More descriptive messages make for easier debugging.
Added "filtering for credentials" messages to the log tests.

We do need to improve those tests, as not everybody has the same tags as me of
course.
Merged pull request #244
Fixed PHP-632: MongoDB::authenticate() no longer attempts to
authenticate, and doesn't return anything either

Now we actually attempt to establish an connection to the server,
with the provided credentials to authenticate.
Since we run the authenticate command internally using that wrapper
we fake the userland return results to be consistent with previous
driver versions and the documentation.
Added a few more comments.
Merged pull request #245
Fixed several tests that are broken when executed in authenticated environment
Merged pull request #246
Fixed PHP-633: findAndModify sometimes throws exception on success

Looks like we are getting a float back from the server, which we
are accessing like a unconverted normal long
Although I cannot reproduce this, I suspect this to be the issue
Merged pull request #247
BUMP 1.3.2RC1
Windows doesn't have strndup

So: s/strndup/zend_strndup
Fixed package.xml file.
Back to -dev.
Fixed PHP-634: Mongo PHP v1.3 fails w/mongoDB 1.6

Oooold versions (1.6.x f.e.) of MongoDB do not include the
maxBsonObjectSize field in the ismaster response (or at all
for that matter). To support those versions we need to have an default
value, 4mb (better be safe then sorry here!) C# and other drivers
use the same value as their defaults.

Surprisingly enough, all the standalone tests pass just fine - with
the exception of reordered associative array keys, different error
messages, and missing features.