error handling for WiflyControl::Fw..() functions

- completed exception handling for firmware functions of WiflyControl
- begun exception harmonization of bootloader functions of WiflyControl

Something to keep in mind:
I think Trace(bla) followed by an Exception(bla) is redundant. if we throw an exception we dont need any trace.If we need more detailed information on where the exception occurred we have to add that information to the exception. I will remove these kind of redundancy when refactoring the Bootloader functions.