remove "unknown" as value in presets

[Klumbumbus]

There is *=unknown as value for the following keys in the default preset. I think we should remove them, as this is the same like key not set. It is also not mentioned on most of the wiki pages of these keys.

• lock=unknown
• hide=unknown
• shelter=unknown
• access=unknown
• capacity:parent=unknown
• capacity:women=unknown
• capacity:disabled=unknown
• crossing=unknown
• foot=unknown

Revision: 8005
Repository Root: http://josm.openstreetmap.de/svn
Relative URL: ^/trunk
Last Changed Author: Don-vip
Last Changed Date: 2015-02-03 21:53:19 +0100 (Tue, 03 Feb 2015)
Build-Date: 2015-02-04 02:34:57
URL: http://josm.openstreetmap.de/svn/trunk
Repository UUID: 0c6e7542-c601-0410-84e7-c038aed88b3b
Last Changed Rev: 8005

Identification: JOSM/1.5 (8005 en) Windows 7 32-Bit
Memory Usage: 247 MB / 742 MB (114 MB allocated, but free)
Java version: 1.8.0_31, Oracle Corporation, Java HotSpot(TM) Client VM
VM arguments: [-Djava.security.manager, -Djava.security.policy=file:C:\Program Files\Java\jre1.8.0_31\lib\security\javaws.policy, -DtrustProxy=true, -Djnlpx.home=<java.home>\bin, -Djnlpx.origFilenameArg=C:\Program Files\josm-latest.jnlp, -Djnlpx.remove=false, -Djava.util.Arrays.useLegacyMergeSort=true, -Djnlpx.heapsize=256m,768m, -Djnlpx.splashport=50901, -Djnlpx.jvm=<java.home>\bin\javaw.exe, -Djnlpx.vmargs=LURqYXZhLnV0aWwuQXJyYXlzLnVzZUxlZ2FjeU1lcmdlU29ydD10cnVlAA==]
Program arguments: [--debug]
Dataset consistency test: No problems found

[Klumbumbus]

In 8008/josm:

see #11070 - add validator Other-info for some *=unknown

[Klumbumbus]

In 8023/josm:

fix #11070 - remove "unknown" as value in presets, raise validator message to warning level