#1 xerces 2.8 compile error and fix

[Simon Polstra]

For some reason XMLPullParserImpl.cpp needs to explicitly include
xercesc/sax/Locator.hpp and
xercesc/sax2/Attributes.hpp
when compiling with xercesc 2.8.

Otherwise I get the following error:
g++ -DHAVE_CONFIG_H -I/home/spolstra/sesame/include -I/home/spolstra/sesame/include -D__DE
BUG__ -Wall -Werror -g -MT XMLPullParserImpl.lo -MD -MP -MF .deps/XMLPullParserImpl.Tpo -c
XMLPullParserImpl.cpp -fPIC -DPIC -o .libs/XMLPullParserImpl.o
XMLPullParserImpl.cpp: In member function 'virtual BasicFileLocation XMLPullParserImpl::get
Location()':
XMLPullParserImpl.cpp:149: error: invalid use of undefined type 'const struct xercesc_2_8::
Locator'
XMLParseEvent.h:37: error: forward declaration of 'const struct xercesc_2_8::Locator'
[..etc..]

[Simon Polstra]

XMLPullParserImpl.cpp