[Patch] Display languages in alphabetical order

[GerdP]

What steps will reproduce the problem?

1. Open preferences - Display Settings -> Look and Feel
2. Click on button for "Language"

What is the expected result?

Languages are displayed in sorted order

What happens instead?

Languages are sorted by the locale:

ast, be, bg, ca, ca__valencia, cs, da, de, el, en, en_AU, en_CA, en_GB, es, et, fi, fr, gl, hu, in, it, ja, km, ko, lt, nb, nl, pl, pt, pt_BR, ru, sk, sv, uk, vi, zh_CN, zh_TW]

Please provide any additional information below. Attach a screenshot if possible.

Build-Date:2019-03-22 07:28:53
Revision:14915
Is-Local-Build:true

Identification: JOSM/1.5 (14915 SVN en) Windows 10 64-Bit
OS Build number: Windows 10 Home 1803 (17134)
Memory Usage: 855 MB / 1753 MB (429 MB allocated, but free)
Java version: 1.8.0_191-b12, Oracle Corporation, Java HotSpot(TM) 64-Bit Server VM
Screen: \Display0 1920x1080
Maximum Screen Size: 1920x1080
VM arguments: [-agentlib:jdwp=transport=dt_socket,suspend=y,address=localhost:65465, -ea, -Dfile.encoding=UTF-8]
Program arguments: [--debug]

Plugins:
+ OpeningHoursEditor (34867)
+ apache-commons (34506)
+ buildings_tools (34904)
+ continuosDownload (82)
+ download_along (34869)
+ ejml (34389)
+ geotools (34513)
+ jaxb (34678)
+ jts (34524)
+ o5m (34867)
+ opendata (34911)
+ pbf (34867)
+ poly (34867)
+ reltoolbox (34867)
+ reverter (34930)
+ undelete (34919)
+ utilsplugin2 (34915)

Last errors/warnings:
- W: No configuration settings found.  Using hardcoded default values for all pools.
- E: Handled by bug report queue: java.lang.ClassCastException: javax.swing.UIManager$LookAndFeelInfo cannot be cast to java.lang.Comparable
- E: Handled by bug report queue: java.lang.NullPointerException
- E: Handled by bug report queue: java.lang.ClassCastException: java.util.Locale cannot be cast to java.lang.Comparable
- E: Handled by bug report queue: java.lang.ClassCastException: java.util.Locale cannot be cast to java.lang.String

[GerdP]

The attached patch sorts the displayed languages depending on the current locale.
This makes it easier to find the wanted language.