RFR: 1213: Generic jdk-cpu fixVersion [v2]

[Erik Joelsson]

> This patch does two things.
> 
> 1. Makes "jdk-cpu" a valid JdkVersion in Skara terms. This will allow us to use this generic version as fixversion for our jdk-cpu repos.
> 2. Makes it possible to configure "altfixversions" for a repository in the notifier. If an altfixversion is configured for a branch, then the notifier will not attempt to update any bugs or add any new backports if one of the altfixversions is already found to be fixed.
> 
> The second change is needed to prevent changes being merged from jdk to jdk-cpu from creating new backport records for every change in the jdk repo.
> 
> I removed the test "testIssuePoolOpenVersion" as it was an exact copy of the test preceding it "testIssuePoolVersion".

Erik Joelsson has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains four commits:

 - Merge branch 'master' into SKARA-1213-jdk-cpu
 - Merge branch 'master' into SKARA-1213-jdk-cpu
 - Allow generic jdk-cpu fixVersion
 - Make jdk-cpu a valid JdkVersion

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Changes: https://git.openjdk.java.net/skara/pull/1234/files
 Webrev: https://webrevs.openjdk.java.net/?repo=skara&pr=1234&range=01
  Stats: 202 lines in 8 files changed: 148 ins; 11 del; 43 mod
  Patch: https://git.openjdk.java.net/skara/pull/1234.diff
  Fetch: git fetch https://git.openjdk.java.net/skara pull/1234/head:pull/1234

PR: https://git.openjdk.java.net/skara/pull/1234