[Checkers] Problems with NonNull checker

[Matt Papi]

>  >   * Error messages for class names, when accessing a static variable -- the
>  >    message says that the class name is possibly-null.  This is most of the
>  >    messages, in fact.

It seems that this was caused by (bad) copies of the qualifier
declarations in Daikon's source without meta-annotations (particularly
@TypeQualifier; the framework rejects anything without that so as to
exclude @Deprecated and others from appearing on types).

Deleting the entire "checkers" directory made these errors go away. I
haven't tried updating the qualifier definitions --  that might work,
though you'd probably have to copy checkers.metaquals as well.


>  >   * The checker crashes, after a long delay.  I have not investigated this
>  >    to determine which file(s) are at fault.
>
>  I have a fix for this one. It was caused specifically by the
>  expression "boolean.class"; I fixed it for this and also for
>  expressions like "boolean[].class". I'll put it in SVN asap -- the
>  checker run just finished without any crashes a second ago.

My fix is in SVN now.


- Matt