Merge branch 'development_master' of https://gitup.uni-potsdam.de/dehne/fltrail into development_master

Merge branch 'development_master' of https://gitup.uni-potsdam.de/dehne/fltrail into development_master

it looks like the task answer questions is not finished for all students
however, you seem to be able to go past the execution phase

# Conflicts:
#	gemeinsamforschen/src/test/java/unipotsdam/gf/core/database/UpdateDB.java

fix #57

There were not correct filtered, so all reflection questions that are
not answered from all projects where shown to the user instead of his
own.

group members are now allowed to change group/public portfolio
entries from their group members, because it is something you can add
for group assessment and a group member should be able to change these
entries also, so they can work together on these entries.

this fixes the wall of text for the selection of portfolio entries.
also it adds a button to the portfolio page and also a add group entry
button to the portfolio page itself. With this, it is possible for the
user to create a group portfolio entry with a button click instead of a
visibility change.