Add capability to edit and persist Cellfie preferences (in particular MappingMaster defaults) both globally and per transformation rule file

[csnyulas]

Being able to set MappingMaster configuration option, mostly comprising default values (see [1], [2] and [3]) is key to provide the user better control about the results produced by their transformation rules.

We should have "global" settings (that can be set, for example, in a new "Cellfie" tab of the Protege Preferences) and "local" settings, which are valid for a set of transformation rules. The local settings should be saved in the json file, together with the transformation rules, so that next time someone opens a file containing transformation rules and executes it, on a spreadsheet with similar structure to the one for which it was written for, they will get the same results, regardless how the Protege preferences have been changed.

[1] https://github.com/protegeproject/mapping-master/wiki/MappingMasterDSL#configuration-options [2] https://github.com/protegeproject/mapping-master/wiki/MappingMasterDSL#Reference_Resolution_Configuration_Options [3] https://github.com/protegeproject/mapping-master/wiki/MappingMasterDSL#missing-value-handling

[martinjoconnor]

This would be really cool. I have collected all the attributes in one place:

https://github.com/protegeproject/mapping-master/wiki/MappingMasterDSL#configuration-options

I will try to fill in the documentation for these shortly.