libxml2: Update to version 2.13.5

libxml2: Update to version 2.13.5

- Update from version 2.13.3 to 2.13.5
- Update of rootfile
- Changelog
    2.13.5
	### Regressions
		- xmlIO: Fix reading from non-regular files like pipes (Nick Wellnhofer)
		- xmlreader: Fix return value of xmlTextReaderReadString (Nick Wellnhofer)
		- parser: Fix loading of parameter entities in external DTDs
		  (Nick Wellnhofer)
		- parser: Fix downstream code that swaps DTDs (Nick Wellnhofer)
		- parser: Fix detection of duplicate attributes (Nick Wellnhofer)
		- string: Fix va_copy fallback (Nick Wellnhofer)
	### Bug fixes
		- xpath: Fix parsing of non-ASCII names (Nick Wellnhofer)
    2.13.4
	### Regressions
		- parser: Make unsupported encodings an error in declarations
		- io: don't set the executable bit when creating files (triallax)
		- xmlcatalog: Improved fix for #699
		- Revert "catalog: Fetch XML catalog before dumping"
		- io: Add missing calls to xmlInitParser
		- tree: Restore return value of xmlNodeListGetString with NULL list
		- parser: Fix error handling after reaching limit
		- parser: Make xmlParseChunk return an error if parser was stopped
	### Bug fixes
		- python: Fix SAX driver with character streams
	### Improvements
		- xpath: Make recursion check work with xmlXPathCompile
		- parser: Report at least one fatal error
	### Portability
		- include: Check whether _MSC_VER is defined

Signed-off-by: Adolf Belka <adolf.belka@ipfire.org>
Signed-off-by: Arne Fitzenreiter <arne_f@ipfire.org>