Added if statements for disable/enable-all (#323)
Added if statements for disable/enable-all (#323)

Hio,

I've tested the library and changeInterval seems to work without issue. However I would like to propose that
disableAll / enableAll only work for timers that "run forever", 

subsequent setTimeout with the first one to disableAll timers will cause the rest to stop aswell.
This was more ment as a controll for those "Run forever" timers
blynkkk/blynk-library,blynkkk/blynk-library,ivankravets/blynk-library,ivankravets/blynk-library,ivankravets/blynk-library,blynkkk/blynk-library,blynkkk/blynk-library,ivankravets/blynk-library,ivankravets/blynk-library,blynkkk/blynk-library