improved Permission.java

also changed the comment in instructor.java
Merge remote-tracking branch 'origin/master' into 72675318
complete PermissionAttributes

test not done yet
commit before adjustment of structure
some const params defined
Merge remote-tracking branch 'origin/master' into 72675318
adjusting param names and ids
first draft of instructorPrivileges
verify toJson and fromJson works for new class
setDefault done
finish instructorPrivileges
adding test for instructorPrivileges
adjustment of js
further adjustment of js
completed test for instructorPrivileges
add some more methods and tests
updated FieldValidatorTest
attributeTest
create db file
Merge remote-tracking branch 'origin/master' into 72675318