blob: removed binlog

NB! Now data-sort now bails out at start.
blob: make all bases but one immutable

This is a requirement for binlog removal.
binlog: added tiny binlog replacement

Now all removals are stored in memory for the whole duration of
data-sort.

NB! We need to rework prepare/plain/commit interface to make it work
with imutable bases.
blob: lock bctl on entry removal
blob: added note about rollback on failure
blob: use b->lock for b->bases access
index: do not consider just sorted base an error
index: fix race between data-sort and index lookup
index: whitespace cleanup
index: improved logging
XXX