Removed errors and completed SET functionality.

Important note: untested!
Minor changes,

Renamed handler, added comments.
Added another test.

Added test checks if states will be loaded correctly.
Deleted obsolete comment.
First stage of SET support completed.

More comprehensive tests and comments are missing. Furthermore, there
are still some TODOs to implement.
Added comments and changed StatesMap class.

StatesMap class is now named DeviceStates to enable injecting a Map or a
List object, but using only a single annotation.
Added comments, cleaned code.

Additionally added support for invocation timeout injection.
Merged files
Merged files.