Fixed NPE in PyUnusedLocalInspectionVisitor.visitPyCallExpression()
Don't ignore unused attributes of empty constructors (PY-7527)

This allows to invoke the add field quick-fix on them.
Merge branch 'python-fixes'
save only custom path
avoid settings collisions (pre idea 14 vs idea 14)
import old settings is not important in this case, but will be implemented later
unused code