Use 'set...' notation

[jaredrummler]

It would be a nice feature to use a 'set' prefix instead of 'with'. Many builder patterns I've seen on Android use 'set'. Also, it would be nice to have fields in the builder class be package-local to avoid creating synthetic accessor methods.

[minidmnv]

There is set notation in cofig options, but it can be chosen together with 'with notation', what's a little misleading.
I can add package-local access as config property if it would be accepted eventually.

[Adriansun]

Would like to have this too. Good suggestion.