enhanced for enabling build in a different directory. Added (optional)

* Makefile.am, gentest.py: enhanced for enabling build in
  a different directory.  Added (optional) param to gentest.py
  to specify the source directory (bug #155468)
* doc/Makefile.am: changed destination of NEWS from (top_srcdir)
  to (top_builddir) (bug #155468)
* python/Makefile.am, python/generator.py: enhanced for enabling
  build in a different directory(bug #155468).  Added (optional)
  param to generator.py to specify the source directory.  Added
  a new table of functions which have possible "foreign" encodings
  (e.g. UTF16), and code to use python 't' format instead of
  'z' format (mostly solving bug #152286, but still need to
  populate the table).
diff --git a/Makefile.am b/Makefile.am
index c8ba4f2..08a052e 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -114,7 +114,8 @@
 testReader_LDADD= $(LDADDS)
 
 testapi.c: gentest.py doc/libxml2-api.xml
-	-@(if [ "$(PYTHON)" != "" ] ; then $(PYTHON) $(srcdir)/gentest.py ; fi )
+	-@(if [ "$(PYTHON)" != "" ] ; then \
+	    $(PYTHON) $(srcdir)/gentest.py $(srcdir) ; fi )
 
 testapi_SOURCES=testapi.c
 testapi_LDFLAGS =