Added fixtures: Generic RGB, Robe Scan 575 XT, Robe Wash 575 XT (thanks to NiKoyes)

Keep generic fixtures all in one group
Fixture address overlapping is no more permitted

Improved fixture: Pro Lights V200
Cache icons for buttons in virtual console (instead of reading them from the filesystem on each repaint)
Make buttons with custom icons always enabled, so they are ful color also in design mode
Store button icon paths relative to workspace (formerly absolute paths)
Added fixtures: Blizzard Lighting Puck Fab5, Blizzard Lighting Snowball (thanks to James Elliott)

Added fixture: High End Systems Studio Command 1200 (thanks to Tony Schuite)
Merge pull request #122 from NiKoyes/master

Update Robe fixtures
Fixed latest Robe fixtures

Removed Stairville PAR 56 10mm. Incomplete.
Merge pull request #123 from janosvitok/button-icons

VC Button icons improvements
Virtual Console Button icons improvements (thanks to Jano Svitok)
Fixing AddFixture code after creating generic RGB fixture.

The tests expected that there is only one generic fixture - generic dimmer.
Also added sorting for the Generic category and unit test runner script.
Merge pull request #124 from janosvitok/generic-rgb-fix

Generic rgb fix
Minor graphics change to address tool
Updated Blizzard Puck Fab5
Added fixtures: High End Systems Technobeam, High End Systems Trackspot, High End Systems Xspot Xtreme, ReelEfx DF-50 (thanks to Louis Gutenschwager)
Added 3 Robe Fixtures
Robin 600E Spot
Robin 600E Wash
Robin 600 LED Wash
(TODO 600E BEAM)