[Tagging] admin_level on ways

[Joseph Eisenberg]

>  I would not want to request to be able to distinguish high and low water in order to be able to map administrative boundaries

But since the administrative boundary is defined by the "Baseline" or
low water springs tide line, that's what should be mapped. Certainly
it is incorrect to add the administrative boundary tags to the same
way as the coastline (or add these ways to a boundary relation) if the
administrative boundary is defined differently - and it almost always
is.

If mappers do not have a good source for administrative boundaries,
they should not be mapped. Usually these need to be imported from an
official source, since they are politically-defined, not based on the
actual, physical shoreline.