[PATCH] Include meters as a valid unit for distance

[naoliv]

​https://wiki.openstreetmap.org/wiki/Key:distance says:

If no unit is given explicitly, the value is assumed to be in kilometers. If another unit is given, it should be separated from the number by a space. Any decimal should be specified using a dot (.) as the decimal separator. Abbreviations for other units are described on the Units page.

And in ​the Units page we can see that the meter (m) is as valid as km, mi and nmi for distance.

One example is on footways and sport tracks where we can see signs marking the distance in meters (for example, distance=50 m, etc)

data/validator/numeric.mapcss

@@ -126 +126 @@
   assertNoMatch: "way maxspeed=variable";
 }
 
-*[distance][distance !~ /^(([0-9]+\.?[0-9]*( (km|mi|nmi))?)|([0-9]+\'[0-9]+\.?[0-9]*\"))$/] {
+*[distance][distance !~ /^(([0-9]+\.?[0-9]*( (m|km|mi|nmi))?)|([0-9]+\'[0-9]+\.?[0-9]*\"))$/] {
   throwWarning: tr("{0}: kilometers is default; period is separator; if units, put space then unit", "distance");
   assertMatch: "way distance=something";
   assertMatch: "way distance=-5";
@@ -257 +257 @@
   assertNoMatch: "node ele=-12.1 m";
   assertNoMatch: "node ele=12";
   assertMatch: "node ele=high";
-}
- No newline at end of file
+}

[Klumbumbus]

In 13035/josm:

fix #15479 - Include meters as a valid unit for distance (patch by naoliv)