Create a normalised Owner name -> ID lookup table

[orta]

trafficstars

In order to offer a URL like http://cocoapods.org/owner/eloyduran we'd need to be able to take the name Eloy Durán from an owner, kill all capitals and de-funny accents etc.

To do this right we need to support people changing names, and the URL needs to continue to work so it is a one owner_id to many normalised names relationship.

This is a part of https://github.com/CocoaPods/cocoapods.org/issues/149

[kylef]

Note, ensure that there is sufficient tests to make sure that when someone registers with the same name they have a different URL.

[segiddins]

Names are already changeable.