Add numerical suffixes for duplicate function names

[cmarczewski]

This would be similar to how IDA Pro handles duplicate function names. Right now it skips duplicates when applying function names with the following message:

": can't rename byte as 'Reset7API' because the name is already used in the program."

The user should be offered the chance to apply the name with an added numerical suffix. This number could be incremented each time the same name is applied to a function.