Revert "Core: GeSica fixes, but no data output. So revert."

This reverts commit b43044b550b2e69aa0c5faad45d30c9aa13e717a.
Revert "Core: Complete new GeSiCa handling, but untested"

This reverts commit a5a8b5c49a773bd35ef6f23a50b031a61adb7b54.