evict session cache both for session entries in the cache (https://github.com/th…

…m-projects/arsnova-backend/wiki/Caching  <-- see List of cache entries and associated keys)

See merge request !20

(https://github.com/thm-projects/arsnova-backend/wiki/Caching
^-- see List of cache entries and associated keys)

add bulk save method for questions (for importing via csv)

This merge request adds a bulk save function for questions. For now, it's only used for the question import via csv to not save every single question with a seperate request.

See merge request !19

In some cases the Socket.IO servers used in test cases are not closed
when starting a new test. In this cases the tests will fail with
an address conflict because an other Socket.IO server is still running.

Using a new port, starting with previous defined port 1234 up to 1243 will
assign every new created Socket.IO server an other address/port.

An address conflict will still occure if an other service is running on
ports from 1234 to 1243, so it is generally a bad idea to have tests in the
hope that no side effects will occure from outside of application scope.

Closes GH-34

In some cases the Socket.IO servers used in test cases are not closed
when starting a new test. In this cases the tests will fail with
an address conflict because an other Socket.IO server is still running.

Using a new port, starting with previous defined port 1234 up to 1243 will
assign every new created Socket.IO server an other address/port.

An address conflict will still occure if an other service is running on
ports from 1234 to 1243, so it is generally a bad idea to have tests in the
hope that no side effects will occure from outside of application scope.

* Fail build on HTTP upload errors
* Undeploy application before deployment
* Fix Tomcat deployment path

Fix session export

fixes the import of sessionFeatures and messages of the day.

See merge request !18

Refac export

This reworks the session import/export to generate the json via backend for performance.

See merge request !16

Conflicts:
	src/main/java/de/thm/arsnova/controller/LecturerQuestionController.java

fix bug where abstention questions are not exported

fix bug where not all attributes from grid questions are exported

implement: via two booleans you can now decide whether AnswerStatistics and FeedbackQuestions shall be exported, too

add empty test methods

add constructors to transport classes to parse "main"class