Mouse doesn't work in Firefox on laptops with *nix OS.

We are waiting for this bugs to be fixed by firefox or sencha teams:

https://www.sencha.com/forum/showthread.php?310206-ExtJ-6-doest-not-work-on-Linux-with-Firefox-45

https://bugzilla.mozilla.org/show_bug.cgi?id=1301327

To make it work:
  - Open "about:config".
  - Find "w3c_touch_events".
  - Reset both settings.
  - Refresh ExtJS 6 page.


Find values:
  * dom.w3c_touch_events.enabled 1
  * dom.w3c_touch_events.expose false


Change them to:
  * dom.w3c_touch_events.enabled 0
  * dom.w3c_touch_events.expose empty
