Changed default development impl to asio.
u2 library update.
Development config for u2py module now uses asio impl

+ Default cash aspp now conforms to service standard.
EVENT_ENCASHMENT added.
ByteArray changes + card_reset implementation

+ ByteArray can now create itself from any ctypes object.
/api/register/encashment added to register
EVENT_ENCASHMENT events.
Implemented constructors for most classes to prepare for
purse initialization.
Implemented constructors for most classes to prepare for transport_card
initialization.