Initial import of xvi-2.47
Add debian/ directory and toplevel Makefile
Make ^R redraw whole screen like ^L instead of just buffer
Fix screen-garbling bug when both IM and IC are defined.

When using xvi on the Debian Linux console or in xterm,
screen updates garbled the screen.

Repeat-by:
$ xvi
ahelo<ESC>hil
Result on screen: "hel l" (with the cursor on the space)

Cause: When both IM/IE and IC were defined, it was using both.
Add "xvi +$" command

The "+$" option was not implemented - it should start the editing session
at the last line of the file. This implements it.

Fix by knassen@sf.net
Modify toplevel Makefile to make it work better from command line

The Makefile was created for the debian package building system;
this change makes it rebuild src/xvi when some source file has changed
and adds an INSTALLROOT variable which users can set to /usr/local if they
like.