Closes#657
- Now SDK downloads N downloads and scan those. And repeat until sync is
done. This safes lot of space of disk used to store downloaded blocks.
- Most changes are done in `CompactBlockProcessor.processNewBlocks`.
- `SyncRanges` structure is changed a bit.
- `SyncStatus` is changed. SDK now report that it's syncing with
progress. It doesn't report each phase of the sync process separately.
Also appropriate notifications were updated.
Address review comments
- Small changes
- Add tests to check computation of processing ranges for single loop
Michal Fousek