use XmlPsiUtil
extracted a bunch of code from XmlEntityRefImpl into XmlEntityCache
extract HtmlPsiUtil out of HtmlUtil
moving stuff to xml-psi-impl
register new stuff in XmlCoreEnvironment
minor moves
remove XmlChangeVisitor and a bunch of related dead code
a few more moves
init WEB-7884 Node.js: breakpoints are not hit, exception on stop debugging (regression)