RFR: Add "binary" jcheck check

[Erik Helin]

Hi all,

this patch adds a new jcheck check called "binary" that checks for binary files.

## Testing
- `sh gradlew test` passes on Linux x86_64
- Added two new unit tests

Thanks,
Erik

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Commits:
 - 8880a50f: Add "binary" jcheck check

Changes: https://git.openjdk.java.net/skara/pull/159/files
 Webrev: https://webrevs.openjdk.java.net/skara/159/webrev.00
  Stats: 228 lines in 7 files changed: 228 ins; 0 del; 0 mod
  Patch: https://git.openjdk.java.net/skara/pull/159.diff
  Fetch: git fetch https://git.openjdk.java.net/skara pull/159/head:pull/159

PR: https://git.openjdk.java.net/skara/pull/159