classes/insane.bbclass: Make .la failures non-fatal the right way, split up the ...

classes/insane.bbclass: Make .la failures non-fatal the right way, split up the .la test in two parts
    -We have a function that can decide if a failure is fatal, use that instead of
     setting sane = True.
    -Test for installed and workdir separately. This allows us to ignore a certain error
     class and complain on others.