Various additions and fixes

- Added server event delegate;
- Added alternative constructors to some event argument classes;
- Changed lots of events;
- Split vProto.Server file/class into multiple files, like
vProto.BaseClient;
- Added proper event code for vProto.Server;
- Added disposal status checks where necessary for vProto.Server and
vProto.BaseClient;
- Documented more classes, properties and methods;
- Removed various 'using' statements from event argument class files.