Support theme variants

[lmihalkovic]

The upcoming Arduino Create looks awesome, and seems to support different color variants. This is about adding the same feature to Arduino IDE.

Note: at the moment the code is still using buttons.gif for the toolbar. It would be nice to replace them with either a simple color mask with the same content, or just code (like for the drop-down and the tabs)

[lmihalkovic]

Credit for the look is entirely going to the Arduino Create designers

[ffissore]

Thank you @lmihalkovic. We won't add support for multiple themes. It's a feature you'll find in Create, not in the IDE

[lmihalkovic]

No problem. It took a few minutes to do it, and i like it as it is.

[lmihalkovic]

[LMDONE]