Added IPAddress.MapToIPv4/6 with tests
IPAddress.Parse() no longer accept single integer values larger than 0xffffffff.
Previously it was claimed that MS accepted up to 0x3fffffffe but a simple test on Windows8 VS2010 did not pass anything larger than 32 bits.

This caused a bug in where two IPv4 addresses with the same 4 bytes would be different, one of them being in the test is now moved to the ipv4ParseWrong list.
Added test EqualsFromBytes to catch it.