Handle class renames

[pingpongboss]

For sure, this is a problem on android. Not sure about apple.

See example output:

## ContinuousPerformance

*removed* interface: `ContinuousPerformance`

*removed* method: `void setIsActiveTokenGenerator(IsActiveTokenGenerator)`

## ContinuousPerforming

*new* interface: `ContinuousPerforming`

*new* method: `void setIsActiveTokenGenerator(IsActiveTokenGenerator)`

apidiff has no way of knowing that ContinuousPerformance was renamed to ContinuousPerforming. The only context it has is that ContinuousPerformance was removed and ContinuousPerforming was added. Ideally, the output should show that ContinuousPerformance was modified to ContinuousPerforming.

One possibility is to allow the user to specify renames on the command line.