Rephrase dialog about failed capabilities/imagery/MOTD request

[RicoElectrico]

Currently, the dialog is not very informative for novice users. Most people don't use proxy anyway. They may have no clue about what capabilities request really is.

The most likely event when this dialog happens is when someone's Internet connection goes down and subsequently they start JOSM.

Therefore, the dialog instead of slapping URLs and Java exceptions in the user's face, should emphasize this can be result of lost Internet connection.

It is also unclear to me how to retry this request in other way than restarting JOSM, when connection goes back up.

Revision: 7643
Repository Root: http://josm.openstreetmap.de/svn
Relative URL: ^/trunk
Last Changed Author: Don-vip
Last Changed Date: 2014-10-21 21:19:16 +0200 (Tue, 21 Oct 2014)
Build-Date: 2014-10-21 19:23:06
URL: http://josm.openstreetmap.de/svn/trunk
Repository UUID: 0c6e7542-c601-0410-84e7-c038aed88b3b
Last Changed Rev: 7643

Identification: JOSM/1.5 (7643 pl) Windows 8.1 64-Bit
Memory Usage: 275 MB / 910 MB (148 MB allocated, but free)
Java version: 1.8.0_25, Oracle Corporation, Java HotSpot(TM) 64-Bit Server VM

Plugins:
- FastDraw (30762)
- FixAddresses (30737)
- HouseNumberTaggingTool (30762)
- OpeningHoursEditor (30737)
- PicLayer (30762)
- ShowInGoogleMaps (8)
- SimplifyArea (30762)
- Tracer2 (30762)
- alignways (30762)
- buildings_tools (30762)
- contourmerge (1012)
- dataimport (30738)
- editgpx (30737)
- imagery_offset_db (30762)
- importvec (30762)
- kendzi3d (1.0.180)
- kendzi3d-jogl (37)
- log4j (30762)
- mapdust (30738)
- measurement (30737)
- mirrored_download (30762)
- notes (v0.9.4)
- pbf (30762)
- photo_geotagging (30762)
- poly (30738)
- reverter (30737)
- surveyor2 (29210)
- terracer (30737)
- turnrestrictions (30762)
- undelete (30762)
- utilsplugin2 (30762)
- wikipedia (30738)

Last errors/warnings:
- W: Failed to load http://wms.misek.pl/maps/, use cached file and retry next time: java.net.UnknownHostException: wms.misek.pl
- E: java.net.UnknownHostException: api.openstreetmap.org
- E: org.openstreetmap.josm.io.OsmTransferException: Nie można połączyć się z serwerem OSM. Sprawdź swoje połączenie z Internetem.. Przyczyna: java.net.UnknownHostException: api.openstreetmap.org
- E: java.net.UnknownHostException: api.openstreetmap.org
- W: org.openstreetmap.josm.io.OsmTransferException: Nie można połączyć się z serwerem OSM. Sprawdź swoje połączenie z Internetem.. Przyczyna: java.net.UnknownHostException: api.openstreetmap.org

[skyper]

See #5765.

[Don-vip]

move tickets that have not been treated this month to next milestone