Arduino IDE 1.8.4

IDE

• IDE Toolbar can now go full width on 4K display.
• Environment variable LIBRARY_INDEX_URL is now correctly parsed (LIBRARY_INDEX_URL_GZ can also be optinally specified). Thanks @xardael
• Added per-board generic option in config file boards.txt for disabling control of dtr+rts. Thanks @d-a-v
• CLI: fixed missing "runtime.platform.path" when running without the --board option
• Linux: fixed desktop icon not launching the IDE in certain Window Managers (thanks @herrold)
• Allow setting low values for console size (correctly applies console.lines=x in preferences.txt)
• Make Preference window fit 600px height displays
• Fix error when renaming an unsaved, newly added file. Thanks @matthijskooijman
• Added the ability to increase/decrease font size via keyboard + mouse shortcuts (Ctrl + MouseWheel)
• Sketch names starting with a digit are now allowed
• Serial monitor is opened on a default position if the multi-monitor setup change (this should fix cases
  when the serial monitor is opened outside of the visibile space)

Libraries

• Fixed wrong folder name for "Adafruit Circuit Playground" library, now it can be updated cleanly.
• Fixed wrong include for "RobotIRRemote", now it should not interfere anymore with the real IRRemote.