Improvments to default directories

[NickDraper]

Add a userSearch.Directories key this is for mask files grouping files etc, and would clear the datasearch purely for data files.

You would need to add anther argument to the file property, and enum to select which directory list to use (data, user, None).

You should be able to override these values in the configService in C++ (changes them for this session).

The python interface should allow users to alter these through a settings function on the FrameworkManager.

Perhaps add a save functionality to the ConfigService to save altered values to the user.properties file.

[NickDraper]

This issue was originally trac ticket 1024