Network version initiated.

Todo:
1. Refactor.
2. Optimise the GUI.
3. Fix bugs.
GUI optimise

1. Add mode choose.
2. Refactor base network, incomplete.
GUI optimise & Refactor.

1. Single mode complete.
2. Refactor shape create by design pattern of factory.
Connection establish succeed.
Exchange random seed complete.
Network mode's base function complete.