DEBUG: Add HashTable::operator<<, expand StoredValue::operator<<

DEBUG: Add HashTable::operator<<, expand StoredValue::operator<<

Also fix some formatting on the existing output. Example from dump():

  HashTable[0x104cd4010] with numInMemory:3 numDeleted:2 values:
    OSV @0x104cd1e30 ... WDN.. temp:    seq:5 rev:2 key:"ns:0 1" exp:0 vallen:0
    OSV @0x104cd1de0 ... WDN.. temp:    seq:4 rev:2 key:"ns:0 0" exp:0 vallen:0
    OSV @0x104cd1e80 ... W.N.. temp:    seq:3 rev:1 key:"ns:0 2" exp:0 vallen:2 val:"2"

Change-Id: I8794f0565bf8280d6019443329b5c04730722cb6
Reviewed-on: http://review.couchbase.org/76187
Reviewed-by: Jim Walker <jim@couchbase.com>
Tested-by: Build Bot <build@couchbase.com>