RFR: 91: Avoid discarding pending items of different types

[Robin Westberg via github.com]

Hi all,

Please review this change that stops the BotRunner from discarding pending WorkItems in favor of newer ones of a different type, even though they cannot be run concurrently.

Best regards,
Robin

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Commits:
 - 358ed180:	Avoid discarding a pending workitem in favor of one with a different type

Pull request:
https://git.openjdk.java.net/skara/pull/108

Webrev:
https://webrevs.openjdk.java.net/skara/108/webrev.00

Patch:
https://git.openjdk.java.net/skara/pull/108.diff

Fetch command:
git fetch https://git.openjdk.java.net/skara pull/108/head:pull/108