WFS protocol's read method should respect readOptions and pass them to the format

[ahocevar]

While it is possible to configure the WFS protocol with readOptions, these will only be passed to the format if they have an output property. This ticket proposes that readOptions can also be passed to the protocol's read method, and that they will always be passed to the format.

With this change, applications will be able to use a configured WFS protocol to e.g. determine the hit count:

protocol.read({
    readOptions: {output: "object"},
    resultType: "hits",
    maxFeatures: null,
    callback: function(resp) {
        // process resp.numberOfFeatures here
    }
});

[ahocevar]

Tests pass in Safari 5. Thanks for any review.

[bartvde]

Andreas, this looks good to go. Only comment I have is can we also get rid of the two other occurences of:

obj.options = {};

in the tests/Protocol/WFS.html?

[ahocevar]

r10947