Removed ability to configure tabs indent from Options dialog. This 'feature'

Removed ability to configure tabs indent from Options dialog.  This 'feature'
has never worked and no one has complained.  It is still possible to set a
default tabs (v. spaces) indent 'manually' via config-main.def (or to turn on
tabs for the current EditorWindow via the Format menu) but IDLE will encourage
indentation via spaces.

Enable setting the indentation width using the Options dialog.
Bug # 783877

Remove some commented out old code from configDialog.py (related to old
methods for invoking the HelpBrowser).

M EditorWindow.py
M NEWS.txt
M configHandler.py