bug#6387: 24.0.50; ESC TAB should be bound to `isearch-complete'

[Drew Adams]

In isearch.el, we have this:
(define-key map "\M-\t" 'isearch-complete)
 
We should also have this, so `ESC TAB' works too:
(define-key map [escape tab] 'isearch-complete)

In GNU Emacs 24.0.50.1 (i386-mingw-nt5.1.2600)
 of 2010-06-07 on 3249CTO
Windowing system distributor `Microsoft Corp.', version 5.1.2600
configured using `configure --with-gcc (4.4) --no-opt --cflags -Ic:/xpm/include'