Fix up the last of the packaging issues and increase test coverage of systemplayer to 100%

Add this to your merge proposal:
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lp:~raoul-snyman/openlp/re-enable-version-checking-2.4 (revision 2656)
[SUCCESS] https://ci.openlp.io/job/Branch-01-Pull/1783/
[SUCCESS] https://ci.openlp.io/job/Branch-02-Functional-Tests/1694/
[SUCCESS] https://ci.openlp.io/job/Branch-03-Interface-Tests/1632/
[SUCCESS] https://ci.openlp.io/job/Branch-04a-Windows_Functional_Tests/1388/
...