* Makefile.am: added a dumb rule to able to compile tst.c
  when people submit a sample test program
* xmlschemas.c: applied small patch from Eric Haszlakiewicz
  to document xmlSchemasSetValidErrors() limitations, #141827
* error.c: Add information in generic and structured error
  setter functions that this need to be done per thread #144308
* xmlsave.c: fixed bug whith missing NOTATION(s) serialization
  bug #144162
* doc/xmllint.xml: typo fix #144840
Daniel