Hyperspace replication changes

[Sanjit Jhala]

Changing BDB_DEADLOCK messages to info instead of warning.

Modified BerkeleyDb search path to look for 4.8 release if available

Changes to implement basic replication



Made changes to BerkeleyDbFilesystem so that each txn opens its own DB 
handle to avoid DB_REP_HANDLE_DEAD errors.

Made changes to allow Hyperspace clients to connect to any Hyperspace 
replica and get redirected to master.

http://github.com/sjhalaz/hypertable/commit/5a6817e89162362d0b0f5c645c7d752a1092e7c0

-Sanjit