Part 3 of ledger servicebility improvement:
Update common/ledger to use error handling framework

Change-Id: I86383b404941c5f922fa2f26ca71af4d91351d4c
Signed-off-by: Wenjian Qiao <wenjianq@gmail.com>

https://jira.hyperledger.org/browse/FAB-2022



This changes introduced by this CR
- Moves the block storage code from package
core/ledger/blkstorage to common/ledger/blkstorage

- Splits the ledger_interface.go so as to move common interfaces
and data type to common/ledger package

- Moves some of the util functions to common/ledger package

- Moves core/ledger/ordererledger package to orderer/ledger/fsledger
orderer folks can futher rename/refactor this as seems suitable to them

Change-Id: I759e16f00dc2ec9bb62196121083cf48eae76948
Signed-off-by: manish <manish.sethi@gmail.com>

FAB-853

Ledger is removed from
   . core/peer/peer.go
   . core/rest/api.go

Ledger package itself is removed. "ledgernext" is
replaced with "ledger".

Change-Id: Ie7dfbd9bf94afa0031aef759fc46929e4fb3b400
Signed-off-by: Srinivasan Muralidharan <muralisr@us.ibm.com>

This commit allows a block stream consumer read across multiple files.

Change-Id: I1bd053e8d022bf1daf01f61f9e3e1ae1629e334b
Signed-off-by: manish <manish.sethi@gmail.com>

(Rocks) DB WAL adds overheads while using the DB for saving checkpoints
for block storage. Avoiding writing to WAL translates the write workload
(appending blocks to the blockfile) into a sequential disk writes.

This commit changes the way checkpoints are saved - checkpoints are
written to DB as before, however since WAL is disabled, the checkpoint
stays in-memory only. The in-memory checkpoint is flushed explicitly to
disk (via DB flush) at the time of new block file creation. The in-memory
checkpoint would implicitly also be flushed to memory at the time of DB
shutdown. However, if a crash takes place, the checkpoint available in the
DB would be behind the actual block file status. In order to handle this
crash scenario, this commit also adds code to perform a scan of the block
file beyond the last saved checkpoint and update the checkpoint.

Change-Id: Ie88646b225abaa50b595833f5e7ed8d4facae920
Signed-off-by: manish <manish.sethi@gmail.com>

This includes structure of the new code conforming to new architecture
and a basic working implementation.

Change-Id: I885e122c0001ff82301cd1448a7ddad80db931b0
Signed-off-by: manish <manish.sethi@gmail.com>