JOSM may check in "You have encountered an error in JOSM." whatever user is using latest JOSM

[mkoniecz]

"You have encountered an error in JOSM." instructs user to "make sure you have updated to the latest version of JOSM".

But nowadays JOSM is able to check whatever new version appeared ("You are using version '7254' of JOSM. The current stable snapshot is 7182 and 7254 is the unstable development version." in welcome window).

Could JOSM check whatever new version appeared and

• on outdated version: mention necessity of updating, skip information how bug may be reported
• on updated version: skip "make sure you have updated to the latest version of JOSM" message and mention only updating plugins
• on inability to check version (no internet, JOSM server is down): display current version

It would reduce tl;dr problem.

Repository Root: http://josm.openstreetmap.de/svn
Build-Date: 2014-06-20 01:36:37
Last Changed Author: simon04
Revision: 7254
Repository UUID: 0c6e7542-c601-0410-84e7-c038aed88b3b
URL: http://josm.openstreetmap.de/svn/trunk
Last Changed Date: 2014-06-19 11:09:04 +0200 (Thu, 19 Jun 2014)
Last Changed Rev: 7254

Identification: JOSM/1.5 (7254 en) Windows 7 32-Bit
Memory Usage: 54 MB / 247 MB (21 MB allocated, but free)
Java version: 1.7.0_55, Oracle Corporation, Java HotSpot(TM) Client VM

Plugin: OpeningHoursEditor (30416)
Plugin: RoadSigns (30495)
Plugin: buildings_tools (30485)
Plugin: continuosDownload (28565)
Plugin: lakewalker (30416)
Plugin: measurement (30416)
Plugin: notes (v0.9.2)
Plugin: wikipedia (30449)

[Don-vip]

In 7401/josm:

fix #10175 - ask for JOSM update in case of crash with old version