Workaround race conition in uDMX driver

Avoid deadlock if device is closed before thread has started

Signed-off-by: Paul Brook <paul@nowt.org>
Merge pull request #281 from tornel/translation

Spanish Translation (monitor)
Merge pull request #279 from pbrook/master

Workaround race conition in uDMX driver
WebAccess: added slider's event to be used on a touchscreen
Monitor: show channel's icon in DMX view mode
Fix angles for American DJ Sweeper Beam Quad LED
Fix Tilt channel for heads in ADJ Sweeper Beam, improve unit tests.

Temporary fix, pan/tilt channels are currently required to be added to every head;
the goal is that the global pan/tilt stay unassigned to any head.
Updated Czech translation
Merge pull request #282 from lachmex/master

Updated Czech translation
ConsoleChannel: simplified code and used stylesheets for channels button. This fixes also Qt5 compatibility

Show intensity icon for poor dimmers
Added fixture: American DJ Inno Spot LED (thanks to Paul Hill)
Added fixture: American DJ Sweeper Beam LED (thanks to George Qualley)
Fix crash
Added stub files for Catalan translation
Fixture Editor: don't allow smart people to cheat the name check
Fixture Editor: fixed weight and lens values save/load
Fixture Editor improvements:

- added missing channel name check on edit
- assign a progressive number on copy/paste a channel
Update german translations
Merge pull request #284 from kripton/german

Update german translations
Translate german strings in remaining .ts files