An admin can add or remove buttons from the TinyMCE editor toolbar

Test steps:
1. Log in as an administrator and navigate to Settings>Site administration>Plugins>Text editors>TinyMCE HTML editor>General settings
2. In the editor toolbar box, remove "bold" and save the changes.
3. Go to a course or anywhere you will use the text editor and verify the "bold" feature is no longer available.
4. Navigate back to Settings>Site administration>Plugins>Text editors>TinyMCE HTML editor>General settings
5. To the right of "table", add "anchor" and save the changes.
6. Go back to an instance of the text editor and verify that you now have the anchor icon to the right of the table icon.
7. Navigate back to Settings>Site administration>Plugins>Text editors>TinyMCE HTML editor>General settings
8. Empty the editor toolbar box and then paste in the items under "default"
9. Return to your text editor and verify the toolbar has "bold" again and no anchor (ie, restored to default)