move soco.py to soco/core.py

the __all__ in __init__.py ensures that all imports continue to work
remove trailing spaces
add plugin base class and example implementation
send_command() and parse_error() should return sth
Fix to make seek method accept H:MM:SS as well as HH:MM:SS
add docstring to SoCoPlugin.name property
add plugin documentation
Add get_group_coordinator, __get_topology methods to allow for the retrieveal of the IP address of the Sonos system that is coordinator for the group containing a specified zone
safely/robustly encode to 8bit string as utf8 from unicode
Add get_group_coordinator, __get_topology methods to allow for the retrieveal of the IP address of the Sonos system that is coordinator for the group containing a specified zone
use really_utf8 in __get_topology
adhere to variable naming conventions and provide url-to-ip split comment
address coding style issues
Merge pull request #5 from daubman/topo_coordinator

Add get_group_coordinator, __get_topology - breaking up commits into separate topical pull requests
Merge pull request #6 from daubman/safe_encode

safely/robustly encode to 8bit string as utf8 from unicode
Merge remote-tracking branch 'upstream/master' into unittest
Added unit test framework/execution script
Added first iteration unittests for 38% of the methods in SoCo
Added title to metadata to adhere to new requirements
Merge pull request #18 from KennethNielsen/fix_tunein_example

Added title to metadata to adhere to new requirements