Extended remote file reader to handle extensionless image urls and querystring parameters for remote URLs

New properties for whitelist: <add url="http://maps.googleapis.com"
extensionLess="true" imageFormat="png" />
Sample URL for extensionless/paramter remote image:
http://localhost:49788/remote.axd?http://maps.googleapis.com/maps/api/staticmap?center=52.341055,7.125435&zoom=13&sensor=false&size=600x300&key=AIzaSyCMKi4DyRB2N-j-Sm3LpZkl6rSXWP_G5ZE?width=600
A 3rd querystring part (here: width=600) if the remote image url has url
parameters