Merge of "moved refresh type from library to core and added send() methods to Items"

Signed-off-by: Alex Tugarev <telekom@tugarev.de>
Fixed bug in ChannelUID.getThingUID

Signed-off-by: Alex Tugarev <telekom@tugarev.de>
Added listener notification on add/remove of ThingProvider

Signed-off-by: Alex Tugarev <telekom@tugarev.de>