elfgcchack.h: add xmlXPathNodeEval and xmlXPathSetContextNode

(after rebuild in doc)
elfgcchack.h: more legacy needs xmlSAX2StartElement() and xmlSAX2EndElement()
win32/libxml2.def.src after rebuild in doc
fix some tabs mixing incompatible with python3
remove HAVE_CONFIG_H dependency in testlimits.c
AC_CONFIG_FILES and executable bit
fix memory leak xml header encoding field with XML_PARSE_IGNORE_ENC

When the xml parser encounters an xml encoding in an xml header while
configured with option XML_PARSE_IGNORE_ENC, it fails to free memory
allocated for storing the encoding.
The patch below fixes this.
How to reproduce:
1. Change doc/examples/parse4.c to add xmlCtxtUseOptions(ctxt,
XML_PARSE_IGNORE_ENC); after the call to xmlCreatePushParserCtxt.
2. Rebuild
3. run the following command from the top libxml2 directory:
LD_LIBRARY_PATH=.libs/ valgrind --leak-check=full
./doc/examples/.libs/parse4 ./test.xml , where test.xml contains
following
input:
<?xml version="1.0" encoding="UTF-81" ?><hi/>
valgrind will report:
==1964== 10 bytes in 1 blocks are definitely lost in loss record 1 of 1
==1964==    at 0x4C272DB: malloc (in
/usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==1964==    by 0x4E88497: xmlParseEncName (parser.c:10224)
==1964==    by 0x4E888FE: xmlParseEncodingDecl (parser.c:10295)
==1964==    by 0x4E89630: xmlParseXMLDecl (parser.c:10534)
==1964==    by 0x4E8B737: xmlParseTryOrFinish (parser.c:11293)
==1964==    by 0x4E8E775: xmlParseChunk (parser.c:12283)

Signed-off-by: Bart De Schuymer <bart at amplidata com>
Fix for CVE-2014-3660

Issues related to the billion laugh entity expansion which happened to
escape the initial set of fixes
Forgot to add the cmake Makefile
Release of libxml2-2.9.2