Introduce 'MethodCall'

[bobalicious]

Lots of methods take:

• Class Name
• Method Name
• Parameter Names
• Parameter Values

Feels like this could be better represented by a class, thus simplifying the signature of 'verify'

Potentially, this is actually the CallLogEntry class, which is currently named too specifically (what it's for, rather than what it is).

Look at renaming CallLogEntry to MethodCall

This means a CallLog would be a list of MethodCall, which seems to still make sense.