Calculate avarage feedback value instead of depending on seperate event

Socket.IO is used to minimize overhead. It does not make any sense to
transmit additinal data which can be calculated in one line of code.
Rejoin session on Socket.IO reconnect event
Refactor app startup and authentication handling

This fixes extremly slow and bugged QR login.
Disable routing after app startup, fix app#checkPreviousLogin
Correcly join session via SIO later when connection has not been
established
Fix feedback average calculation
Use WebSocket support detection, SIO related code cleanup
Fix Patterns for .gitattributes to correctly ignore libraries
Apply .gitattributes
Fix CAS logout
Fix routing for Facebook login
Merge branch 'customization' into integration

Conflicts:
	src/main/webapp/app/controller/Auth.js
	src/main/webapp/app/proxy/RestProxy.js
	src/main/webapp/app/view/LoginPanel.js
	src/main/webapp/app/view/MatrixButton.js
	src/main/webapp/app/view/Question.js
	src/main/webapp/app/view/TabPanel.js
	src/main/webapp/app/view/about/TabPanel.js
	src/main/webapp/app/view/feedback/AskPanel.js
	src/main/webapp/app/view/home/MySessionsPanel.js
	src/main/webapp/app/view/speaker/InClass.js
	src/main/webapp/app/view/speaker/NewQuestionPanel.js
	src/main/webapp/app/view/speaker/QuestionStatisticChart.js
	src/main/webapp/app/view/speaker/form/ExpandingAnswerForm.js
	src/main/webapp/app/view/user/InClass.js
Merge branch 'socket.io-1.0' into integration

Conflicts:
	src/main/webapp/app/proxy/RestProxy.js
	src/main/webapp/lib/socket.io/socket.io.min.js
Merge branch 'skillquestion-image' into integration

Conflicts:
	src/main/webapp/app/view/speaker/NewQuestionPanel.js
Hide learning progress components if feature is disabled by config
Fix correct answer count on grid square form