Refactored; restructured; abstracted

- vProto.Server became vProto.BaseServer - only contains common server
functionality;
- Properly abstractized vProto.BaseClient and vProto.BaseServer;
- The default vProto.Server and vProto.Client classes are gone - they
were too limiting;
- Added a server and client class for each protocol stack - so far
TCP/IP and SSL/TCP/IP;
- Removed currently unused vProto.IHandleServer and vProto.IHandleClient
interfaces - there are still some unused classes left whose future is
yet undecided;
- Spread the variables and disposal logic where it should actually be;
- The server and client base classes use protected abstract or virtual
methods to perform their intended functionality;
- All the classes except the SSL/TCP/IP server and client can be
inherited and extended;
- Reduced amount of junk/unused code.