Help for keyboard shortcut should consider the operating system

[flaimo]

As seen on the attached screenshot the help for the keyboard shortcuts seem to be hardcoded, but those are wrong when working on a Mac, where "cmd" is used instead of "ctrl"

Tooltips and helper strings, as also the help pages should be dynamic an show the correct shortcuts for the operating system currently used.

Revision: 8279
Repository Root: http://josm.openstreetmap.de/svn
Relative URL: ^/trunk
Last Changed Author: Klumbumbus
Last Changed Date: 2015-04-26 22:42:34 +0200 (Sun, 26 Apr 2015)
Build-Date: 2015-04-27 01:31:19
URL: http://josm.openstreetmap.de/svn/trunk
Repository UUID: 0c6e7542-c601-0410-84e7-c038aed88b3b
Last Changed Rev: 8279

Identification: JOSM/1.5 (8279 en) Mac OS X 10.10.3
Memory Usage: 471 MB / 910 MB (258 MB allocated, but free)
Java version: 1.8.0_45, Oracle Corporation, Java HotSpot(TM) 64-Bit Server VM
VM arguments: [-Djava.library.path=/Applications/JOSM.app/Contents/MacOS, -DLibraryDirectory=/Users/flaimo/Library, -DDocumentsDirectory=/Users/flaimo/Documents, -DApplicationSupportDirectory=/Users/flaimo/Library/Application Support, -DCachesDirectory=/Users/flaimo/Library/Caches, -DSandboxEnabled=false, -Dapple.laf.useScreenMenuBar=true, -Dcom.apple.macos.use-file-dialog-packages=true, -Dcom.apple.macos.useScreenMenuBar=true, -Dcom.apple.mrj.application.apple.menu.about.name=JOSM, -Dcom.apple.smallTabs=true]
Dataset consistency test: No problems found

Plugins:
- ColorPlugin (1414145445)
- HouseNumberTaggingTool (30892)
- OpeningHoursEditor (30962)
- PicLayer (30962)
- RoadSigns (30977)
- ShapeTools (1000)
- areaselector (1429449787)
- buildings_tools (31100)
- contourmerge (1013)
- geotools (31068)
- jts (31002)
- log4j (30892)
- measurement (30892)
- opendata (31050)
- reverter (30990)
- terracer (30892)
- turnlanes (30892)
- turnrestrictions (31034)
- undelete (30892)
- utilsplugin2 (31072)
- wikipedia (31035)

Last errors/warnings:
- W: Could not get presets icon presets/vending_machine.png
- E: Failed to locate image 'presets/vending_machine.png'
- W: Could not get presets icon presets/vending_machine.png
- E: Failed to locate image 'presets/shelter.png'
- W: Could not get presets icon presets/shelter.png

[Don-vip]

In 8359/josm:

fix #11422 - Help for keyboard shortcut should consider the operating system + do not display unrelevant messages if recent added tags are disabled