mlUnit mlUnit

Prevent setpath leaking variables or deleting previously defined ones

Update failure sample output

Improve documentation

Update deprecate documentation and comments

@mlunit_gui renamed from gui_test_runner, by straight renaming, crossed fingers

Rename reflect to mlunit_reflect

fail() renamed into mlunit_fail(), so as not to shadow other functions
that may well call themselves fail

failures also handled by @mlunit_errorinfo

Improve in-code comments

Update CHANGES.txt