extra/grep: add post-deinstall script that restores busybox links

extra/grep/APKBUILD

@@ -2,15 +2,16 @@
 # Maintainer:
 pkgname=grep
 pkgver=2.5.4
-pkgrel=0
+pkgrel=1
 pkgdesc="Searches input files for lines containing a match to a specified pattern"
 url="http://www.gnu.org/software/grep/grep.html"
 license="GPL"
 depends="uclibc pcre"
 makedepends="pcre-dev"
-install=
+install="$pkgname.post-deinstall"
 subpackages="$pkgname-doc"
-source="http://mirrors.kernel.org/gnu/$pkgname/$pkgname-$pkgver.tar.gz"
+source="http://mirrors.kernel.org/gnu/$pkgname/$pkgname-$pkgver.tar.gz
+	$install"
 
 build() {
 	cd "$srcdir/$pkgname-$pkgver"
@@ -25,4 +26,5 @@ build() {
 
 }
 
-md5sums="92258031d98d4f12dfc6a6d24057e672  grep-2.5.4.tar.gz"
+md5sums="92258031d98d4f12dfc6a6d24057e672  grep-2.5.4.tar.gz
+b84506d253e04db3c5af9016fead45a3  grep.post-deinstall"

extra/grep/grep.post-deinstall

@@ -0,0 +1,3 @@
+#!/bin/sh
+
+busybox --install -s