Allow examples and test-suite to be built out of source tree

- Examples/Makefile.in rules use SRCDIR as the relative source directory

- ./config.status replicates Examples/ source directory tree in build
  directory, and copies each Makefile to build directory, prefixed with
  a header which sets SRCDIR to source directory

- Examples/test-suite/.../Makefile.in set SRCDIR from Autoconf-set srcdir

- Examples/test-suite/errors/Makefile.in needs to filter out source
  directory from SWIG error messages

- Lua: embedded interpreters are passed location of run-time test

- Python: copy run-time scripts to build directory because of 2to3
  conversion; import_packages example copies __init__.py from source
  directory; test-suite sets SCRIPTDIR to location of run-time tests

- Javascript: binding.gyp renamed to binding.gyp.in so that $srcdir
  can be substituted with SRCDIR; removed './' from require() statements
  so that NODE_PATH can be used to point Node.js to build directory

Examples/javascript/pointer/Makefile

@@ -1,3 +1,3 @@
 SRCS = example.cxx
 
-include ../example.mk
+include $(SRCDIR)../example.mk

Examples/javascript/pointer/binding.gyp

@@ -1,8 +0,0 @@
-{
-  "targets": [
-    {
-      "target_name": "example",
-      "sources": [ "example.cxx", "example_wrap.cxx" ]
-    }
-  ]
-}

Examples/javascript/pointer/binding.gyp.in

@@ -0,0 +1,9 @@
+{
+  "targets": [
+    {
+      "target_name": "example",
+      "sources": [ "$srcdir/example.cxx", "example_wrap.cxx" ],
+      "include_dirs": ["$srcdir"]
+    }
+  ]
+}

Examples/javascript/pointer/example.js

@@ -1 +1 @@
-module.exports = require("./build/Release/example");
+module.exports = require("build/Release/example");

Examples/javascript/pointer/runme.js

@@ -1,4 +1,4 @@
-var example = require("./example");
+var example = require("example");
 
 // First create some objects using the pointer library.
 console.log("Testing the pointer library");