Merge changes I32e255a1,I63a9372c,I73856faa,I3145e451,I8b28c684, ...

* changes:
  e2fsdroid: Don't over-reserve blocks for files in Base FS.
  e2fsdroid: Skip Base FS entries that no longer exist.
  e2fsdroid: Allow re-use of deduplicated blocks.
  e2fsdroid: Do not allocate invalid blocks from BaseFS.
  e2fsdroid: Refactor basefs allocation.
  e2fsdroid: Refactor block_range.