outsource the tiger underlay from the internal mappaint style to an external mappaint style

[Klumbumbus]

The underlay disturbs the mappaint in JOSM for the whole USA.
According to ​https://wiki.openstreetmap.org/wiki/TIGER_to_OSM_Attribute_Map#Misc_Attribute_Pairs the tiger:reviewed=no tag has nearly completely failed:

tiger:reviewed=no was set on all ways in the TIGER import. It is intended as a way of tracking TIGER fixup progress. However it does not succeed in this aim and is largely pointless.

Some people remove this tag to indicate that they have reviewed (and perhaps corrected) the imported TIGER data. Some people set the value to yes. Some people set the value to 'aerial', indicating that they used aerial imagery to check/fix the location.

There is some support within JOSM and Potlatch for differing displays according to this tag.

However TIGER fixup is quite laborious enough without having to fiddle with this tag, so many people don't bother doing anything, in order to make faster progress with the fixup itself. Others object to the tag since it implies a process of review and "moderation" of edits, which does not exist (and we're proud that it doesn't exist). Some people don't modify the tag because they simply don't know about it. All this means that the tag is not an accurate indication of anything, and developers of tools such as TIGER Edited Map have developed different more reliable ways of seeing areas which need fixup.

So for all who use the underlay can use the new external style and for all who don't care about the tiger:reviewed=no tag the mappaint is much improved.