reconstruct all the code of QWSChat

same as title, but not much change in code, but make it more concise and
easy to understand.
Rename some of the files and put all files about QWebsocket into one file.
Change the GUI, make it resizable and not destroy the layout of the widgets.
Merge branch 'master' of github.com:PeterYHChen/WSChat
small change in the initiateLoginDlg function

make it run smooth even when there's no internet