Improving error messages when an annotation processor crashes.

[lahodaj]

Improving error messages when an annotation processor crashes and clear AP cache on failure.

• use printStackTrace(writer) to format exception
• add jar location, AP name and javac version to exception message
• use update advice message for APs with known compatibility issues (e.g lombok) but generic failure msg by default

example:

[mbien]

thanks for looking into this. The key puzzle piece was the fact that printMessage() wouldn't display in UI when no element was passed as parameter. Given that it was already used that way (but it didn't work?), I assumed It must be me looking at the wrong place.

I made some changes on top of this PR:

• switch back to generic (but improved) AP message: even though the changes here are mainly due to lombok, lets try to make the improvements useful for all APs
• use SourceVersion.latest().runtimeVersion().feature() instead of constant as msg parameter
• use printStackTrace(writer) to format exception to make it look "native"
• add jar location, AP name and javac version to exception message
• clear class cache on AP failure

commit would be at https://github.com/mbien/netbeans/tree/improve-ap-error-messages, let me know what you think.

[mbien]

added commit, rebased, updated PR text with screenshot.

changes:

• back to two messages, one with update advice for APs with known compatibility issues like lombok and for all other failures the same msg just without advice.
• cache is cleared on all failures

would be good to squash after review