tuntap: recommend upstream signed binary.

We have an upstream signed binary available! Big big love to Mattias
for this.

This PR converts all the existing tuntap dependencies into
binary-friendly tuntap dependencies, and adds a tuntap dependency to
requirements to look for the kexts.

Closes Homebrew/legacy-homebrew#33894.

Signed-off-by: Mike McQuaid <mike@mikemcquaid.com>

Formula/iodine.rb

@@ -12,7 +12,7 @@ class Iodine < Formula
     sha1 "1afe02179eaa83f66382eaf296023c574e351f79" => :lion
   end
 
-  depends_on "tuntap"
+  depends_on :tuntap
 
   def install
     system "make", "install", "prefix=#{prefix}"

Formula/miredo.rb

@@ -5,7 +5,7 @@ class Miredo < Formula
   url "http://www.remlab.net/files/miredo/miredo-1.2.6.tar.xz"
   sha1 "630c84e9919952f6f4792ceda54a12e0aef43bbf"
 
-  depends_on "tuntap"
+  depends_on :tuntap
   depends_on "judy"
 
   patch :DATA

Formula/openvpn.rb

@@ -14,7 +14,7 @@ class Openvpn < Formula
   end
 
   depends_on "lzo"
-  depends_on "tuntap"
+  depends_on :tuntap
   depends_on "openssl"
 
   def install
@@ -41,8 +41,9 @@ def install
   end
 
   def caveats; <<-EOS.undent
-    Make sure to follow the directions given by `brew info tuntap`
-    before trying to use OpenVPN.
+    If you have installed the Tuntap dependency as a source package you will
+    need to follow the instructions found in `brew info tuntap`. If you have
+    installed the binary Tuntap package, no further action is necessary.
 
     For OpenVPN to work as a server, you will need to create configuration file
     in #{etc}/openvpn, samples can be found in #{share}/doc/openvpn

Formula/peervpn.rb

@@ -7,7 +7,7 @@ class Peervpn < Formula
   sha1 "45f815445a2d654e2da56de965633743d25f3468"
 
   depends_on "openssl"
-  depends_on "tuntap"
+  depends_on :tuntap
 
   patch :DATA if MacOS.version == :snow_leopard
 

Formula/shrewsoft-vpn-client.rb

@@ -20,7 +20,7 @@ class ShrewsoftVpnClient < Formula
 
   depends_on "cmake" => :build
   depends_on "openssl"
-  depends_on "tuntap"
+  depends_on :tuntap
   depends_on "qt" if build.with? "gui"
 
   def install

Formula/vpnc.rb

@@ -11,7 +11,7 @@ class Vpnc < Formula
   depends_on "libgcrypt"
   depends_on "libgpg-error"
   depends_on "gnutls"
-  depends_on "tuntap"
+  depends_on :tuntap
 
   fails_with :llvm do
     build 2334