fix property types in language test

Change-Id: I2c802699ab8db6d7286ccc58b364656145129b11
Reviewed-by: Christian Kandeler <christian.kandeler@digia.com>
split overridden values off the build configuration

Property values in profiles now serve as default values for module
values. Property values given on the command line override properties
that are specified in files.
This way it is possible to specify a property value in a profile but
override it in a file or on the command line.
The hierarchy is profile < file < command line.

Change-Id: I786ef5a215312779ed1b79ed64f856b82c612403
Reviewed-by: Christian Kandeler <christian.kandeler@digia.com>
fix overriding of stringList properties

Task-number: QBS-369

Change-Id: I602551ed740a81279412cc631c5e35f601a46903
Reviewed-by: Christian Kandeler <christian.kandeler@digia.com>