RFR: 6902: Console plug-ins with icons not found will fail

[Marcus Hirt]

The tab will get a null pointer during initialization and not show up at all. Currently the PDE plug-in will not
properly include icon resources in the generated projects. That's a separate issue that will have to be looked into.

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Commit messages:
 - 6902: Console plug-ins with icons not found will fail

Changes: https://git.openjdk.java.net/jmc/pull/108/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jmc&pr=108&range=00
  Issue: https://bugs.openjdk.java.net/browse/JMC-6902
  Stats: 8 lines in 1 file changed: 7 ins; 0 del; 1 mod
  Patch: https://git.openjdk.java.net/jmc/pull/108.diff
  Fetch: git fetch https://git.openjdk.java.net/jmc pull/108/head:pull/108

PR: https://git.openjdk.java.net/jmc/pull/108