improve visual feedback when working in (stacked) pattern mode

[thijz]

These days i'm using H2 more and more for live performances in stacked pattern mode
Using a midi controller i can enable/disable patterns and stack them anyway i want
This works quite well, but i have 2 suggestions for improving the visual feedback

1. When you are playing live it is currently hard to see the black triangle left of the pattern name that indicates that the pattern is enabled. Therefore i would like to change the color to something that is easy to see like green

2. the triangle only indicates that the pattern is active, there is no indication that is has been 'armed'
   therefore i would like to add a second indicator that shows that the pattern will be enabled at next loop

i have made a mock up of 1) and 2) combined :

Let me explain the 5 stages :

1. pattern is not selected and is not armed
2. a button on the midi controller has been pressed so the yellow triangle lights up, indicating that the pattern has been armed
3. at the next loop the pattern actually starts to play (= the green triangle lights up)
4. some time later the midi button is pressed again and the pattern is no longer armed (= the yellow triangle goes off)
5. at the next loop the pattern stops playing

[trebmuh]

Great idea!

[theGreatWhiteShark]

Implemented in #1544