Introduces presets which avoid much of the previous configuration
duplication. The original import files are now thin wrappers around
the themepark themes.
Defining a tag as deleteable/extratag and main tag is mutually exclusive
and deleting certain key/value combinations to exclude them from being
used as a main tag is confusing. By merging the handling, such
excludes can now be made explicit in the main list.
By using the same lookup table, it is now also possible to have a
short-cut for uninteresting objects.
