Automatically enable User Pictures option

Since this module doesn't fire any code unless the User Pictures option is enabled at admin/user/settings, and since this option is disabled by default, it might be nice to either:
a) Warn the user if this option is disabled, note that it is required, and point them to the user settings page to turn it on.
b) Automatically enable it when the module is initially installed.

Here's a patch that does b). I removed the watchdog message when the module is installed since that's not something I'd seen other modules do, so it looked like debugging code. If not, feel free to add it back. :)