Admin screen handles are too generic

[markjaquith]

You may want to look into making the handles of the various admin screens less generic. For instance, "attributes" is far too generic. Better to prefix them with "woo-" or "wc-".

You'll see some strange bugs if another plugin is using the same handle. You don't want things like that rolling into support.

[mikejolley]

Thanks for noticing. Fixed.