Add autoconf, automake, libtool & perl shims

Refs #304

Author: mxcl

libexec/autoconf

@@ -0,0 +1,11 @@
+#!/bin/sh
+
+if [ -x /usr/local/bin/pkgx ]; then
+  # removed from PATH deliberately
+  pkgx=/usr/local/bin/pkgx
+else
+  # probs this is running in pkgx CI/CD
+  pkgx="${PKGX_DIR:-$HOME/.pkgx}/pkgx.sh/v*/bin/pkgx"
+fi
+
+exec "$pkgx" +gnu.org/autoconf -- autoconf "$@"

libexec/automake

@@ -0,0 +1,11 @@
+#!/bin/sh
+
+if [ -x /usr/local/bin/pkgx ]; then
+  # removed from PATH deliberately
+  pkgx=/usr/local/bin/pkgx
+else
+  # probs this is running in pkgx CI/CD
+  pkgx="${PKGX_DIR:-$HOME/.pkgx}/pkgx.sh/v*/bin/pkgx"
+fi
+
+exec "$pkgx" +gnu.org/automake -- automake "$@"

libexec/libtool

@@ -0,0 +1,16 @@
+#!/bin/sh
+
+# linking on darwin is best left to Apple’s choices
+if [ $(uname) = "Darwin" ]; then
+  exec /usr/bin/libtool "$@"
+fi
+
+if [ -x /usr/local/bin/pkgx ]; then
+  # removed from PATH deliberately
+  pkgx=/usr/local/bin/pkgx
+else
+  # probs this is running in pkgx CI/CD
+  pkgx="${PKGX_DIR:-$HOME/.pkgx}/pkgx.sh/v*/bin/pkgx"
+fi
+
+exec "$pkgx" +gnu.org/libtool -- libtool "$@"

libexec/perl

@@ -0,0 +1,11 @@
+#!/bin/sh
+
+if [ -x /usr/local/bin/pkgx ]; then
+  # removed from PATH deliberately
+  pkgx=/usr/local/bin/pkgx
+else
+  # probs this is running in pkgx CI/CD
+  pkgx="${PKGX_DIR:-$HOME/.pkgx}/pkgx.sh/v*/bin/pkgx"
+fi
+
+exec "$pkgx" +perl.org -- perl "$@"