Add support for liking and un-liking statuses by allowing users to add
and remove stars/likes to them.
The user can also view a list of statuses that they've liked.
Changes:
- Move InvalidListRepliesPolicyError, InvalidTimelineCategory,
InvalidStatusVisibility and InvalidStatusContentTypeError type to the
model package.
- Clean up some code in regards to the parsing of the Enum types.
- Clean up the error messages sent back to the user.
- Use colons instead of semicolons when unwrapping error messages.
- Print errors to Standard Error (os.Stderr)
