Engine: don't crash on non existant audio files
[WIP] Improving the QLC+ Script function

- ScriptEditor: commented non-finished macros
- Added systemcommand, to hook up QLC+ with the execution of external programs/scripts
- Written totally missing documentation about Script/Script Editor
- improved setfixture channel selection

TODO:
- add random() macro
- add file selection macro
- check paths with spaces (especially on Windows). They should break the tokenizer method
- display a syntax error log when loading/modifying a script
- improve wait and setfixture macros using standard QLC+ dialogs/widgets
- evaluate the jump macro started by Heikki (even though I predict more disasters than benefits)
- add line numbers ?
[WIP] More Script function improvements

- added random macro
- added file path macro
- wait times use the QLC+ way for times
- updated/fixed documentation

TODO
now it's really necessary to have a check for
- spaces in file paths
- syntax errors
Virtual Console/Audio Triggers: fixed incorrect number of bars when reconfiguring the widget

Virtual Console/Audio Triggers: multiple triggers at the same time and with different number of bars are now supported
RGB Matrix Editor: correctly update colors when the algorithm is changed

Fixed layout issues on VCAudioTriggers and VCCueList
Fixed VCAudioTriggers wrong QObject connection
Added functionStarting signal and stopFunction method to VCAudioTriggers to use them in a Solo Frame
Virtual Console/Audio Triggers: fixed behaviour on a solo frame
Engine/Script: use paths between quotes and correctly parse them

This fixes the use of paths with whitespaces
Fixed Script paths usage in Windows

Fixed Windows build
Updated Script Editor documentation
Updated translations (UI)
soloframe: can have multiple buttons associated to the same function

ALSO: fix adding/removing buttons during virtual console live edit
(buttons were not connected, now they are)

Conflicts:

	ui/src/virtualconsole/vcsoloframe.cpp
addwidgetinpage should always be called
update changelog

Conflicts:

	debian/changelog
integrate vcaudiotrigger in soloframe compatible widgets
fix soloframe signal connections when copying and changing multipage mode
fix loading
better cleanup of removed widgets
Merge pull request #416 from plugz/soloframe-fix-2

Virtual Console/Solo Frame: can have multiple buttons associated to the same function