Editor footer toolbar
Currently we have no way to display or change the highlight mode or tab width. We should have this via a toolbar just below the text editor box.
Add a toolbar for selecting highlight mode and tab size, using the simple javascript functions documented at https://ace.c9.io/#nav=howto to complete the action on the current tab.
Highlight mode: https://help.gnome.org/misc/release-notes/3.12/figures/gedit.png
Tab width: https://upload.wikimedia.org/wikipedia/commons/thumb/e/ef/Gedit_3.11.92.png/300px-Gedit_3.11.92.png
As in the above photo tab width selection should offer 2, 4, and 8 spaces plus an option for "Use Spaces" (which should default to TRUE and change the soft tabs option).
Submit your .js file and modified along with the necessary changes to templates/editor.xslt (see https://hg.copyleftgames.org/gci/file/tip/templates/editor.xslt ).