New arch: use $.mapael to get mapconf

[Indigo744]

As discussed in #117
Check both $.mapael and $.fn.mapael and warn the user if extending the later.

[neveldo]

Hello,

Thank you for your PR, I think that the previous check for the map should be removed at line 251 :

        if ($.fn[pluginName].maps[options.map.name] === undefined) {
            throw Error("Unknown map '" + options.map.name + "'");
        }

[Indigo744]

Right, this is corrected :)