Motivation:
The new ByteBuf interface contains methods to get values independent to the current buffer byte order setting. This approach generate less garbage by not creating SwappedByteBuf when default protocol endian is different from BE.

Modifications:
- Added new methods to the ByteBuf interface.
 getShort
 getUnsignedShort
 getMedium
 getUnsignedMedium
 getInt
 getUnsignedInt
 getLong
 getChar
 getFloat
 getDouble
- Implemented added methods to the AbstractByteBuf, EmptyByteBuf, SwappedByteBuf, WrappedByteBuf, ReplayingDecoderBuffer

Result:
ByteBuf interface has new getters with demanded byte order argument.
 - coding style checked
 - implementing more setters