- added abstract numeric type for shared method between int and uint
- distinction between uint and int in getType
- added two new subclasses for SoldityType
- added two testcases for int and uint SoldityType

- fixed StandaloneBlockchainTest#encodeTest1 as the expectation was
wrong

- formatting
- throw exception if a biginteger below zero is encoded to uint
- made old regression test encode1 visible again
- reuse of Hex-encoding in test

- formatting
- license intro added to test