Expands ProfileManager and profile unit tests.

Adds methods for deleting, creating, and listing
profiles. Also modifies get_profile by adding
an extra arg to specify whether a non-existing profile 
should be auto-created.

Adds related unit tests to test_profile.

Methods added:
- create_profile
- list_profiles
- delete_profile

Related to https://github.com/Freeseer/freeseer/pull/632
I added it to make sure there was distinction between a create profile request, and a get profile request in the config API. For the case of an already-existing profile, get will return that profile, but create will thrown an exception. Does that make sense?