Log Message:
Update to 2.6.30:

* Portability: Solaris crash on error handling, windows path fixes
(Roland Schwarz and Rob Richards), mingw build (Roland Schwarz)

* Bugfixes: xmlXPathNodeSetSort problem (William Brack), leak when
reusing a writer for a new document (Dodji Seketeli), Schemas
xsi:nil handling patch (Frank Gross), relative URI build problem
(Patrik Fimml), crash in xmlDocFormatDump, invalid char in comment
detection bug, fix disparity with xmlSAXUserParseMemory, automata
generation for complex regexp counts problems, Schemas IDC import
problems (Frank Gross), xpath predicate evailation error handling
(William Brack)