Make LuaPlayer.map_view_settings RW and also allow access to the new 1.1 filters

[templar4522]

The reason for this request is to be able to toggle these filters programmatically, or to block/allow things depending on a filter being active or not.

A concrete example would be my mod that adds tags by rightclicking like before 1.1. When the tag filter is off and I add a tag, I should either be consistent with the official tagging behaviour, ie turning the filter on after adding the tag, or prevent the tag from being added. At the moment I can do neither thing as I can't read the flags as it is write only, and I can't write as there is no identifier for it.