Merge branch 'origin/next'
Preference dialog split into two dialogs.
Both the two new dialogs and the old one are active and working at the same time. The old one will be removed when everything is in place.
New preference icons are added for classical theme.
Placeholder icons added for all monochrome themes.
The only thing not moved is the splash screen functionality. It does not really fit in either dialog and there are allready another special dialog for customizing splash screens. Perhaps make a combined dialog for all splash screen work? Will think about it tomorrow.
Split of preferences completed.
Old preferences still left for testing (last checking with that).
Work started on updating the splash editor.
Merge branch 'origin/next'

Conflicts:
	companion/src/apppreferencesdialog.cpp
	companion/src/apppreferencesdialog.h
	companion/src/apppreferencesdialog.ui
	companion/src/fwpreferencesdialog.ui
	companion/src/imgpreferences.ui
	companion/src/mainwindow.cpp
Splash Editor modified
Editor getting some functionality
Merge branch 'origin/next'

Conflicts:
	companion/src/translations/companion_pl.ts
Updated translation
Merge pull request #661 from opentx/dvogonen/simplify_companion_preferences_dialog_632

Dvogonen/simplify companion preferences dialog 632