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/test-suite/octave/Makefile.in

@@ -4,10 +4,17 @@
 
 LANGUAGE     = octave
 OCTAVE       = @OCTAVE@
+SCRIPTDIR    = $(srcdir)
 SCRIPTSUFFIX = _runme.m
+
 srcdir       = @srcdir@
 top_srcdir   = @top_srcdir@
 top_builddir = @top_builddir@
+ifeq (.,$(srcdir))
+SRCDIR =
+else
+SRCDIR = $(srcdir)/
+endif
 
 CPP_TEST_CASES += \
 	li_std_pair_extra \
@@ -33,7 +40,7 @@ include $(srcdir)/../common.mk
 
 # Overridden variables here
 LIBS       = -L.
-CSRCS      = $(srcdir)/octave_empty.c
+CSRCS      = octave_empty.c
 
 # Custom tests - tests with additional commandline options
 # none!
@@ -57,8 +64,8 @@ CSRCS      = $(srcdir)/octave_empty.c
 # Runs the testcase. A testcase is only run if
 # a file is found which has _runme.m appended after the testcase name.
 run_testcase = \
-	if [ -f $(srcdir)/$(SCRIPTPREFIX)$*$(SCRIPTSUFFIX) ]; then \
-	  env LD_LIBRARY_PATH=.:$$LD_LIBRARY_PATH OCTAVE_PATH=$(srcdir):$$OCTAVE_PATH $(RUNTOOL) $(OCTAVE) $(srcdir)/$(SCRIPTPREFIX)$*$(SCRIPTSUFFIX); \
+	if [ -f $(SCRIPTDIR)/$(SCRIPTPREFIX)$*$(SCRIPTSUFFIX) ]; then \
+	  env LD_LIBRARY_PATH=.:$$LD_LIBRARY_PATH OCTAVE_PATH=$(srcdir):$$OCTAVE_PATH $(RUNTOOL) $(OCTAVE) $(SCRIPTDIR)/$(SCRIPTPREFIX)$*$(SCRIPTSUFFIX); \
 	fi
 
 # Clean: remove the generated .m file