Do not reuse old connections.

- Only keep connections in the cache for a limited time
  (currently 10 minutes).
- Always get connection manager from the cache, don't keep
  a reference in the EasServerConnection.

Also add some logging.

Bug: 11249423
Change-Id: I7c7da95745770fd2cb3ba58d63fc1fcdcc8eb232
4 files changed