Corrections so that the documentation confirms to the DTD
Change encoding of troublesome notes.xml files to utf-8

Most notes.xml files will be updated in every release and cause
the kind of the problems described in the previous commit.
Merge branch 'bjorn/xml-encoding-fix/OTP-11310' into maint

* bjorn/xml-encoding-fix/OTP-11310:
  Change encoding of troublesome notes.xml files to utf-8
  Convert some notes.xml files from latin-1 to utf-8