add a lock to calls to load_manifest - apparently, it's not thread safe

fixes #103 and #108
Merge pull request #139 from T045T/develop

add a lock to calls to load_manifest - apparently, it's not thread safe
changelog updated
0.6.8
request_id --> id
removed service_module
service_type --> type
service_name --> service
stop_service --> unadvertise_service
service_request --> reuse of call_service (previously defined)
matches original call_service
matches original call_service
cleanup init function
rewrite of advertise service
protocol documented for advertise service functions
Merge pull request #143 from RobotWebTools/advertise-service-cleanup

Advertise service cleanup
changelog updated
0.7.0
Merge pull request #144 from RobotWebTools/develop

0.7.0