make dbaccess implementation fully configurable at instantiation time

[jknack]

DBAccessFactory it is nice for quick start, but will be nice to have a way to manually instantiated/configure DBAccess implementations.

For example make BoltDBAccess fully configurable via constructor:

public BoltDBAccess(Driver driver) {
  ...
}

public BoltDBAccess(String uri, AuthToken token) {
  ...
}

Similar for embedded implementation:

public EmbeddedDBAccess(GraphDatabaseService db) {
  ...
}

Each implementation has a clear contract of what dependencies needs.

Here are some other benefits of such solution:

• Fix #31, due user can manually create and provide they own GraphDatabaseService
• Today the implementations filter out some properties, so we can fully configure a GraphDatabaseService or Driver

What do you think?

[Wolfgang-Schuetzelhofer]

Good idea, I will consider this for the next release.

Best regards