DeleteMultiple will allow metainfo to delete multiple segments
and get the old pointers in a single request.
Change-Id: Ic144f30c5453274fa2b80df2895f123f5a9cc48b
to make them cancelable. Also,
* rename BulkDelete->BulkDeleteAll
this leaves room for a new method `BulkDelete(items storage.Items)` that
does a bulk deletion of a specified list of items, as opposed to
deleting _everything_. such a method would be used in the
`cleanupItems()` function found in utils.go, because when individual
deletes are fairly slow, that step takes way too long during tests.
* use BulkDelete method if available
nothing currently provides `BulkDelete(items storage.Items) error`,
but we made use of it with the Bigtable testing and code, and may make
use of it again when adding new kv backends.
* and eliminate the global context in test_iterate.go
Change-Id: I171c7a3818beffbad969b131e98b9bbe3f324bf2
1. Added KeyValueStore.Iterate for implementing the different List, ListV2 etc. implementations. This allows for more efficient use of memory depending on the situation.
2. Implemented an inmemory teststore for running tests. This should allow to replace MockKeyValueStore in most places.
3. Rewrote tests
4. Pulled out logger from bolt implementation so it can be used for all other storage implementations.
5. Fixed multiple things in bolt and redis implementations.
