Merge pull request #147 from continuum/always-send-auth-credentials-for-basic-auth

Avoid waiting for a WWW-Authenticate under HTTP Basic auth
Merge pull request #146 from continuum/batch-remove-node-property

Add :remove_node_property to batch operations
add DeadlockDetectedException to fix #145
adding constraints to fix #143
Bump to 1.3.9
Merge remote-tracking branch 'upstream/master'

* upstream/master:
  Bump to 1.3.9
  adding constraints to fix #143
  add DeadlockDetectedException to fix #145