New formula: zshdb

New formula for The ZSH Debugger (0.08 and head)

Closes Homebrew/homebrew#17718.

Signed-off-by: Jack Nagel <jacknagel@gmail.com>

Formula/zshdb.rb

@@ -0,0 +1,24 @@
+require 'formula'
+
+class Zshdb < Formula
+  homepage 'https://github.com/rocky/zshdb'
+  url 'http://sourceforge.net/projects/bashdb/files/zshdb/0.08/zshdb-0.08.tar.bz2'
+  sha1 '29f860d0130debe6a966ee1e12f2f3046c78897b'
+
+  head 'https://github.com/rocky/zshdb.git'
+
+  depends_on 'zsh'
+  depends_on :automake if build.head?
+
+  def install
+    if build.head?
+      system "autoreconf", "-fvi"
+      system "autoconf"
+    end
+
+    system "./configure", "--disable-dependency-tracking",
+                          "--prefix=#{prefix}",
+                          "--with-zsh=#{HOMEBREW_PREFIX}/bin/zsh"
+    system "make install"
+  end
+end