Provide all properties to OTA HTML Generator

not only the ones starting with mios.ota-service
Allowing env variables in OTA HTML generation
Remove duplicate flush.
Remove hard coded xcode plugin version in integration test.
Missing close of InputStream
Allowing null properties in OTAManager for tests
1.9.1
Added release notes to github site
1.9.2-SNAPSHOT
Provide unarchiverId from outside.

With the current approach regarding handling of additional bundles/archives
we might run into problems in case of a not commonly used file appendix.
Up to now we use the file appendix of the main artifact in order to derive the
unarchiver.

With the approach implemented here is it possible to provide the unarchiver from
outside. In case no unarchiver is provided the unarchiver is still derived from the
file appendix of the main artifact.