work on languages

- found why default feed rate doesn't change between program loads -
window is created before prefs are read
- added language selection on program start
- added language selection menu in preferences
Scan for and load language files automatically
multilingual stuff

- made system more robust, prevents some failures
- added location hints to language files to help translators
added loading configs without connecting

v3 machines might like to load config without connecting so they can
save to SD card.  This is now possible.