This makes the text and background colors in the editor window
follow the custom colors "Font color" and "Document background"
respectively in Options > LibreOffice > Applications Colors.

... for those who think BASIC looks cooler when written in green
text on black background.

Change-Id: I82647865f7c2915341249c2fd5ebc9bd8d617bd1
Reviewed-on: https://gerrit.libreoffice.org/29815Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: jan iversen <jani@documentfoundation.org>
Tested-by: jan iversen <jani@documentfoundation.org>
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>