Makefile redesigned

- No longer needs updated as files are added/removed from project
- Object files and binaries created in organized directories
- Supports 2 build targets:  'debug' and 'live'
- Not specifying build target builds all
- Will create temp directories if needed instead of stall build process
Added escape clause to game loop
Added some error detection to Session object

- dtor checks state of owned socket object
- invalid login state reported and default assigned on detection
- Session->Write() checks socket is still open before writing
Adjustments after coding lesson

- learning example bug fixed (game loop condition)
- 'make clean' updated to clean C::B objects too
- nickname on new sessions stored