Increased VERSION number as some quite significant changes:

 - gccxml-plugin/plugin/xml.c
    * Fix includes of cxxabi.h and demangle.h
    * Add new xml_plugin_data struct, to pass around data shared between
      different gcc callback stages.
    * Moved some declarations into gccxml_plugin.h
    * Created new functions to init and delete xml_plugin_data struct,
      as well as to begin and end XML dump. This shares some
      responsibility of code all originally in do_xml_dump().
    * Reverted preprocessor tests in xml_print_(de)mangled_attribute,
      which would cause a lot of mangled and demangled XML attributes
      to be missing from output XML.
    * Had to add an extra test for xml_print_(de)mangled_attribute for
      GCC-4.7 and above, as for a couple of C++11 headers, seg faults
      were encountered here. A side-effect is that namespaces won't
      include mangled or demangled attributes in xml output.
    * xml_traverse_decls now includes declarations which satisfy
      DECL_IS_BUILTIN, as well as sub-namespaces.
    * Other changes are mostly superficial.

 - gccxml-plugin/plugin/CMakeLists.txt
    * Add a warning for gcc-4.7, as found libiberty.h was missing on
      Mac OS X development machine.
    * Put source files into own variable.

- gccxml-plugin-plugin/gccxml_plugin.h
    * Include more declarations and fewer includes.

- gccxml-plugin-plugin/gccxml_plugin.c
    * Register a new callback: PLUGIN_FINISH, to free plugin_data
      struct memory.
    * Other changes are mostly superficial, or assist with passing a
      (void*)xml_plugin_data struct to functions in xml.c.