Fixed minor problems caused by tests

Added check for config directory in CloudCode directory - fix #83

Revert "Set an ACL on ParseResource by default"

Default ACL breaks some functionalities.

This reverts commit eb437d98.

Closes #97

closes #95

Set an ACL on ParseResource by default

Also switch ACLs default permissions to public read/write

fixes #97

Make ACL default to master key only

Base Role from Object instead of ParseResource

This gives us everything we need from Object and
reduces code duplication

Add the ability to drop whole classes

implments #100

The last 4 unit tests fail when run in series, but not if they were
run individually. The test for testCanGetCurrentUser registers the
service using the session token which loses the previous registration.
The other tests require that they are registered with the master_key,
so now the testCanGetCurrentUser test re-registers.

User.current_user() when a valid session token is provided

Add config object

Enable Session Tokens to be used to access ACL-protected objects.

Solve Datetime object not JSON serializable

ACL patch

Added Installation channel subscription modification

Handle adding and removing relations by User.

Added Installation channel modification so that account holders can manually add/remove subscriptions of users on their application

Simple fix using "default=" argument of json.dumps to pass a date_handler.

Update README.mkd with Role and ACL documentation.

Handle adding and removing relations from Roles.

This adds addRelation and removeRelation capabilities to Role, making it possible to add users to the users column and roles to the roles column in a Role object, for example. This prevents the error of Role not having the attribute addRelation or removeRelation when trying to add users or roles to a Role, which is critical for Role functionality.

Update datatypes.py to handle dict on properties