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
Makes sense now. Documenting what each method raises will make this more obvious.

See the ["Functions and Methods" section under the "Comments" guidelines](http://google-styleguide.googlecode.com/svn/trunk/pyguide.html?showone=Comments#Comments ) for more info.